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* sctp: donot reset the overall_error_count in SHUTDOWN_RECEIVE statelucien2015-10-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | commit f648f807f61e64d247d26611e34cc97e4ed03401 upstream. Commit f8d960524328 ("sctp: Enforce retransmission limit during shutdown") fixed a problem with excessive retransmissions in the SHUTDOWN_PENDING by not resetting the association overall_error_count. This allowed the association to better enforce assoc.max_retrans limit. However, the same issue still exists when the association is in SHUTDOWN_RECEIVED state. In this state, HB-ACKs will continue to reset the overall_error_count for the association would extend the lifetime of association unnecessarily. This patch solves this by resetting the overall_error_count whenever the current state is small then SCTP_STATE_SHUTDOWN_PENDING. As a small side-effect, we end up also handling SCTP_STATE_SHUTDOWN_ACK_SENT and SCTP_STATE_SHUTDOWN_SENT states, but they are not really impacted because we disable Heartbeats in those states. Fixes: Commit f8d960524328 ("sctp: Enforce retransmission limit during shutdown") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Fix race between OOTB responce and route removalAlexander Sverdlin2015-08-071-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 29c4afc4e98f4dc0ea9df22c631841f9c220b944 ] There is NULL pointer dereference possible during statistics update if the route used for OOTB responce is removed at unfortunate time. If the route exists when we receive OOTB packet and we finally jump into sctp_packet_transmit() to send ABORT, but in the meantime route is removed under our feet, we take "no_route" path and try to update stats with IP_INC_STATS(sock_net(asoc->base.sk), ...). But sctp_ootb_pkt_new() used to prepare responce packet doesn't call sctp_transport_set_owner() and therefore there is no asoc associated with this packet. Probably temporary asoc just for OOTB responces is overkill, so just introduce a check like in all other places in sctp_packet_transmit(), where "asoc" is dereferenced. To reproduce this, one needs to 0. ensure that sctp module is loaded (otherwise ABORT is not generated) 1. remove default route on the machine 2. while true; do ip route del [interface-specific route] ip route add [interface-specific route] done 3. send enough OOTB packets (i.e. HB REQs) from another host to trigger ABORT responce On x86_64 the crash looks like this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [<ffffffffa05ec9ac>] sctp_packet_transmit+0x63c/0x730 [sctp] PGD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: ... CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 4.0.5-1-ARCH #1 Hardware name: ... task: ffffffff818124c0 ti: ffffffff81800000 task.ti: ffffffff81800000 RIP: 0010:[<ffffffffa05ec9ac>] [<ffffffffa05ec9ac>] sctp_packet_transmit+0x63c/0x730 [sctp] RSP: 0018:ffff880127c037b8 EFLAGS: 00010296 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000015ff66b480 RDX: 00000015ff66b400 RSI: ffff880127c17200 RDI: ffff880123403700 RBP: ffff880127c03888 R08: 0000000000017200 R09: ffffffff814625af R10: ffffea00047e4680 R11: 00000000ffffff80 R12: ffff8800b0d38a28 R13: ffff8800b0d38a28 R14: ffff8800b3e88000 R15: ffffffffa05f24e0 FS: 0000000000000000(0000) GS:ffff880127c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000020 CR3: 00000000c855b000 CR4: 00000000000007f0 Stack: ffff880127c03910 ffff8800b0d38a28 ffffffff8189d240 ffff88011f91b400 ffff880127c03828 ffffffffa05c94c5 0000000000000000 ffff8800baa1c520 0000000000000000 0000000000000001 0000000000000000 0000000000000000 Call Trace: <IRQ> [<ffffffffa05c94c5>] ? sctp_sf_tabort_8_4_8.isra.20+0x85/0x140 [sctp] [<ffffffffa05d6b42>] ? sctp_transport_put+0x52/0x80 [sctp] [<ffffffffa05d0bfc>] sctp_do_sm+0xb8c/0x19a0 [sctp] [<ffffffff810b0e00>] ? trigger_load_balance+0x90/0x210 [<ffffffff810e0329>] ? update_process_times+0x59/0x60 [<ffffffff812c7a40>] ? timerqueue_add+0x60/0xb0 [<ffffffff810e0549>] ? enqueue_hrtimer+0x29/0xa0 [<ffffffff8101f599>] ? read_tsc+0x9/0x10 [<ffffffff8116d4b5>] ? put_page+0x55/0x60 [<ffffffff810ee1ad>] ? clockevents_program_event+0x6d/0x100 [<ffffffff81462b68>] ? skb_free_head+0x58/0x80 [<ffffffffa029a10b>] ? chksum_update+0x1b/0x27 [crc32c_generic] [<ffffffff81283f3e>] ? crypto_shash_update+0xce/0xf0 [<ffffffffa05d3993>] sctp_endpoint_bh_rcv+0x113/0x280 [sctp] [<ffffffffa05dd4e6>] sctp_inq_push+0x46/0x60 [sctp] [<ffffffffa05ed7a0>] sctp_rcv+0x880/0x910 [sctp] [<ffffffffa05ecb50>] ? sctp_packet_transmit_chunk+0xb0/0xb0 [sctp] [<ffffffffa05ecb70>] ? sctp_csum_update+0x20/0x20 [sctp] [<ffffffff814b05a5>] ? ip_route_input_noref+0x235/0xd30 [<ffffffff81051d6b>] ? ack_ioapic_level+0x7b/0x150 [<ffffffff814b27be>] ip_local_deliver_finish+0xae/0x210 [<ffffffff814b2e15>] ip_local_deliver+0x35/0x90 [<ffffffff814b2a15>] ip_rcv_finish+0xf5/0x370 [<ffffffff814b3128>] ip_rcv+0x2b8/0x3a0 [<ffffffff81474193>] __netif_receive_skb_core+0x763/0xa50 [<ffffffff81476c28>] __netif_receive_skb+0x18/0x60 [<ffffffff81476cb0>] netif_receive_skb_internal+0x40/0xd0 [<ffffffff814776c8>] napi_gro_receive+0xe8/0x120 [<ffffffffa03946aa>] rtl8169_poll+0x2da/0x660 [r8169] [<ffffffff8147896a>] net_rx_action+0x21a/0x360 [<ffffffff81078dc1>] __do_softirq+0xe1/0x2d0 [<ffffffff8107912d>] irq_exit+0xad/0xb0 [<ffffffff8157d158>] do_IRQ+0x58/0xf0 [<ffffffff8157b06d>] common_interrupt+0x6d/0x6d <EOI> [<ffffffff810e1218>] ? hrtimer_start+0x18/0x20 [<ffffffffa05d65f9>] ? sctp_transport_destroy_rcu+0x29/0x30 [sctp] [<ffffffff81020c50>] ? mwait_idle+0x60/0xa0 [<ffffffff810216ef>] arch_cpu_idle+0xf/0x20 [<ffffffff810b731c>] cpu_startup_entry+0x3ec/0x480 [<ffffffff8156b365>] rest_init+0x85/0x90 [<ffffffff818eb035>] start_kernel+0x48b/0x4ac [<ffffffff818ea120>] ? early_idt_handlers+0x120/0x120 [<ffffffff818ea339>] x86_64_start_reservations+0x2a/0x2c [<ffffffff818ea49c>] x86_64_start_kernel+0x161/0x184 Code: 90 48 8b 80 b8 00 00 00 48 89 85 70 ff ff ff 48 83 bd 70 ff ff ff 00 0f 85 cd fa ff ff 48 89 df 31 db e8 18 63 e7 e0 48 8b 45 80 <48> 8b 40 20 48 8b 40 30 48 8b 80 68 01 00 00 65 48 ff 40 78 e9 RIP [<ffffffffa05ec9ac>] sctp_packet_transmit+0x63c/0x730 [sctp] RSP <ffff880127c037b8> CR2: 0000000000000020 ---[ end trace 5aec7fd2dc983574 ]--- Kernel panic - not syncing: Fatal exception in interrupt Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) drm_kms_helper: panic occurred, switching back to text console ---[ end Kernel panic - not syncing: Fatal exception in interrupt Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: sctp alway uses init_net] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: fix ASCONF list handlingMarcelo Ricardo Leitner2015-08-071-11/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2d45a02d0166caf2627fe91897c6ffc3b19514c4 upstream. ->auto_asconf_splist is per namespace and mangled by functions like sctp_setsockopt_auto_asconf() which doesn't guarantee any serialization. Also, the call to inet_sk_copy_descendant() was backuping ->auto_asconf_list through the copy but was not honoring ->do_auto_asconf, which could lead to list corruption if it was different between both sockets. This commit thus fixes the list handling by using ->addr_wq_lock spinlock to protect the list. A special handling is done upon socket creation and destruction for that. Error handlig on sctp_init_sock() will never return an error after having initialized asconf, so sctp_destroy_sock() can be called without addrq_wq_lock. The lock now will be take on sctp_close_sock(), before locking the socket, so we don't do it in inverse order compared to sctp_addr_wq_timeout_handler(). Instead of taking the lock on sctp_sock_migrate() for copying and restoring the list values, it's preferred to avoid rewritting it by implementing sctp_copy_descendant(). Issue was found with a test application that kept flipping sysctl default_auto_asconf on and off, but one could trigger it by issuing simultaneous setsockopt() calls on multiple sockets or by creating/destroying sockets fast enough. This is only triggerable locally. Fixes: 9f7d653b67ae ("sctp: Add Auto-ASCONF support (core).") Reported-by: Ji Jianwen <jiji@redhat.com> Suggested-by: Neil Horman <nhorman@tuxdriver.com> Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Adjust filename, context - Most per-netns state is global] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix passing wrong parameter header to param_type2af in ↵Saran Maruti Ramanara2015-03-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | sctp_process_param commit cfbf654efc6d78dc9812e030673b86f235bf677d upstream. When making use of RFC5061, section 4.2.4. for setting the primary IP address, we're passing a wrong parameter header to param_type2af(), resulting always in NULL being returned. At this point, param.p points to a sctp_addip_param struct, containing a sctp_paramhdr (type = 0xc004, length = var), and crr_id as a correlation id. Followed by that, as also presented in RFC5061 section 4.2.4., comes the actual sctp_addr_param, which also contains a sctp_paramhdr, but this time with the correct type SCTP_PARAM_IPV{4,6}_ADDRESS that param_type2af() can make use of. Since we already hold a pointer to addr_param from previous line, just reuse it for param_type2af(). Fixes: d6de3097592b ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT") Signed-off-by: Saran Maruti Ramanara <saran.neti@telus.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix slab corruption from use after free on INIT collisionsDaniel Borkmann2015-02-201-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 600ddd6825543962fb807884169e57b580dba208 upstream. When hitting an INIT collision case during the 4WHS with AUTH enabled, as already described in detail in commit 1be9a950c646 ("net: sctp: inherit auth_capable on INIT collisions"), it can happen that we occasionally still remotely trigger the following panic on server side which seems to have been uncovered after the fix from commit 1be9a950c646 ... [ 533.876389] BUG: unable to handle kernel paging request at 00000000ffffffff [ 533.913657] IP: [<ffffffff811ac385>] __kmalloc+0x95/0x230 [ 533.940559] PGD 5030f2067 PUD 0 [ 533.957104] Oops: 0000 [#1] SMP [ 533.974283] Modules linked in: sctp mlx4_en [...] [ 534.939704] Call Trace: [ 534.951833] [<ffffffff81294e30>] ? crypto_init_shash_ops+0x60/0xf0 [ 534.984213] [<ffffffff81294e30>] crypto_init_shash_ops+0x60/0xf0 [ 535.015025] [<ffffffff8128c8ed>] __crypto_alloc_tfm+0x6d/0x170 [ 535.045661] [<ffffffff8128d12c>] crypto_alloc_base+0x4c/0xb0 [ 535.074593] [<ffffffff8160bd42>] ? _raw_spin_lock_bh+0x12/0x50 [ 535.105239] [<ffffffffa0418c11>] sctp_inet_listen+0x161/0x1e0 [sctp] [ 535.138606] [<ffffffff814e43bd>] SyS_listen+0x9d/0xb0 [ 535.166848] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b ... or depending on the the application, for example this one: [ 1370.026490] BUG: unable to handle kernel paging request at 00000000ffffffff [ 1370.026506] IP: [<ffffffff811ab455>] kmem_cache_alloc+0x75/0x1d0 [ 1370.054568] PGD 633c94067 PUD 0 [ 1370.070446] Oops: 0000 [#1] SMP [ 1370.085010] Modules linked in: sctp kvm_amd kvm [...] [ 1370.963431] Call Trace: [ 1370.974632] [<ffffffff8120f7cf>] ? SyS_epoll_ctl+0x53f/0x960 [ 1371.000863] [<ffffffff8120f7cf>] SyS_epoll_ctl+0x53f/0x960 [ 1371.027154] [<ffffffff812100d3>] ? anon_inode_getfile+0xd3/0x170 [ 1371.054679] [<ffffffff811e3d67>] ? __alloc_fd+0xa7/0x130 [ 1371.080183] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b With slab debugging enabled, we can see that the poison has been overwritten: [ 669.826368] BUG kmalloc-128 (Tainted: G W ): Poison overwritten [ 669.826385] INFO: 0xffff880228b32e50-0xffff880228b32e50. First byte 0x6a instead of 0x6b [ 669.826414] INFO: Allocated in sctp_auth_create_key+0x23/0x50 [sctp] age=3 cpu=0 pid=18494 [ 669.826424] __slab_alloc+0x4bf/0x566 [ 669.826433] __kmalloc+0x280/0x310 [ 669.826453] sctp_auth_create_key+0x23/0x50 [sctp] [ 669.826471] sctp_auth_asoc_create_secret+0xcb/0x1e0 [sctp] [ 669.826488] sctp_auth_asoc_init_active_key+0x68/0xa0 [sctp] [ 669.826505] sctp_do_sm+0x29d/0x17c0 [sctp] [...] [ 669.826629] INFO: Freed in kzfree+0x31/0x40 age=1 cpu=0 pid=18494 [ 669.826635] __slab_free+0x39/0x2a8 [ 669.826643] kfree+0x1d6/0x230 [ 669.826650] kzfree+0x31/0x40 [ 669.826666] sctp_auth_key_put+0x19/0x20 [sctp] [ 669.826681] sctp_assoc_update+0x1ee/0x2d0 [sctp] [ 669.826695] sctp_do_sm+0x674/0x17c0 [sctp] Since this only triggers in some collision-cases with AUTH, the problem at heart is that sctp_auth_key_put() on asoc->asoc_shared_key is called twice when having refcnt 1, once directly in sctp_assoc_update() and yet again from within sctp_auth_asoc_init_active_key() via sctp_assoc_update() on the already kzfree'd memory, which is also consistent with the observation of the poison decrease from 0x6b to 0x6a (note: the overwrite is detected at a later point in time when poison is checked on new allocation). Reference counting of auth keys revisited: Shared keys for AUTH chunks are being stored in endpoints and associations in endpoint_shared_keys list. On endpoint creation, a null key is being added; on association creation, all endpoint shared keys are being cached and thus cloned over to the association. struct sctp_shared_key only holds a pointer to the actual key bytes, that is, struct sctp_auth_bytes which keeps track of users internally through refcounting. Naturally, on assoc or enpoint destruction, sctp_shared_key are being destroyed directly and the reference on sctp_auth_bytes dropped. User space can add keys to either list via setsockopt(2) through struct sctp_authkey and by passing that to sctp_auth_set_key() which replaces or adds a new auth key. There, sctp_auth_create_key() creates a new sctp_auth_bytes with refcount 1 and in case of replacement drops the reference on the old sctp_auth_bytes. A key can be set active from user space through setsockopt() on the id via sctp_auth_set_active_key(), which iterates through either endpoint_shared_keys and in case of an assoc, invokes (one of various places) sctp_auth_asoc_init_active_key(). sctp_auth_asoc_init_active_key() computes the actual secret from local's and peer's random, hmac and shared key parameters and returns a new key directly as sctp_auth_bytes, that is asoc->asoc_shared_key, plus drops the reference if there was a previous one. The secret, which where we eventually double drop the ref comes from sctp_auth_asoc_set_secret() with intitial refcount of 1, which also stays unchanged eventually in sctp_assoc_update(). This key is later being used for crypto layer to set the key for the hash in crypto_hash_setkey() from sctp_auth_calculate_hmac(). To close the loop: asoc->asoc_shared_key is freshly allocated secret material and independant of the sctp_shared_key management keeping track of only shared keys in endpoints and assocs. Hence, also commit 4184b2a79a76 ("net: sctp: fix memory leak in auth key management") is independant of this bug here since it concerns a different layer (though same structures being used eventually). asoc->asoc_shared_key is reference dropped correctly on assoc destruction in sctp_association_free() and when active keys are being replaced in sctp_auth_asoc_init_active_key(), it always has a refcount of 1. Hence, it's freed prematurely in sctp_assoc_update(). Simple fix is to remove that sctp_auth_key_put() from there which fixes these panics. Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix race for one-to-many sockets in sendmsg's auto associateDaniel Borkmann2015-02-201-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 2061dcd6bff8b774b4fac8b0739b6be3f87bc9f2 upstream. I.e. one-to-many sockets in SCTP are not required to explicitly call into connect(2) or sctp_connectx(2) prior to data exchange. Instead, they can directly invoke sendmsg(2) and the SCTP stack will automatically trigger connection establishment through 4WHS via sctp_primitive_ASSOCIATE(). However, this in its current implementation is racy: INIT is being sent out immediately (as it cannot be bundled anyway) and the rest of the DATA chunks are queued up for later xmit when connection is established, meaning sendmsg(2) will return successfully. This behaviour can result in an undesired side-effect that the kernel made the application think the data has already been transmitted, although none of it has actually left the machine, worst case even after close(2)'ing the socket. Instead, when the association from client side has been shut down e.g. first gracefully through SCTP_EOF and then close(2), the client could afterwards still receive the server's INIT_ACK due to a connection with higher latency. This INIT_ACK is then considered out of the blue and hence responded with ABORT as there was no alive assoc found anymore. This can be easily reproduced f.e. with sctp_test application from lksctp. One way to fix this race is to wait for the handshake to actually complete. The fix defers waiting after sctp_primitive_ASSOCIATE() and sctp_primitive_SEND() succeeded, so that DATA chunks cooked up from sctp_sendmsg() have already been placed into the output queue through the side-effect interpreter, and therefore can then be bundeled together with COOKIE_ECHO control chunks. strace from example application (shortened): socket(PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP) = 3 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(1)=[{"hello", 5}], msg_controllen=0, msg_flags=0}, 0) = 5 sendmsg(3, {msg_name(28)={sa_family=AF_INET, sin_port=htons(8888), sin_addr=inet_addr("192.168.1.115")}, msg_iov(0)=[], msg_controllen=48, {cmsg_len=48, cmsg_level=0x84 /* SOL_??? */, cmsg_type=, ...}, msg_flags=0}, 0) = 0 // graceful shutdown for SOCK_SEQPACKET via SCTP_EOF close(3) = 0 tcpdump before patch (fooling the application): 22:33:36.306142 IP 192.168.1.114.41462 > 192.168.1.115.8888: sctp (1) [INIT] [init tag: 3879023686] [rwnd: 106496] [OS: 10] [MIS: 65535] [init TSN: 3139201684] 22:33:36.316619 IP 192.168.1.115.8888 > 192.168.1.114.41462: sctp (1) [INIT ACK] [init tag: 3345394793] [rwnd: 106496] [OS: 10] [MIS: 10] [init TSN: 3380109591] 22:33:36.317600 IP 192.168.1.114.41462 > 192.168.1.115.8888: sctp (1) [ABORT] tcpdump after patch: 14:28:58.884116 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [INIT] [init tag: 438593213] [rwnd: 106496] [OS: 10] [MIS: 65535] [init TSN: 3092969729] 14:28:58.888414 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [INIT ACK] [init tag: 381429855] [rwnd: 106496] [OS: 10] [MIS: 10] [init TSN: 2141904492] 14:28:58.888638 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [COOKIE ECHO] , (2) [DATA] (B)(E) [TSN: 3092969729] [...] 14:28:58.893278 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [COOKIE ACK] , (2) [SACK] [cum ack 3092969729] [a_rwnd 106491] [#gap acks 0] [#dup tsns 0] 14:28:58.893591 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [DATA] (B)(E) [TSN: 3092969730] [...] 14:28:59.096963 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SACK] [cum ack 3092969730] [a_rwnd 106496] [#gap acks 0] [#dup tsns 0] 14:28:59.097086 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [DATA] (B)(E) [TSN: 3092969731] [...] , (2) [DATA] (B)(E) [TSN: 3092969732] [...] 14:28:59.103218 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SACK] [cum ack 3092969732] [a_rwnd 106486] [#gap acks 0] [#dup tsns 0] 14:28:59.103330 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [SHUTDOWN] 14:28:59.107793 IP 192.168.1.115.8888 > 192.168.1.114.35846: sctp (1) [SHUTDOWN ACK] 14:28:59.107890 IP 192.168.1.114.35846 > 192.168.1.115.8888: sctp (1) [SHUTDOWN COMPLETE] Looks like this bug is from the pre-git history museum. ;) Fixes: 08707d5482df ("lksctp-2_5_31-0_5_1.patch") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: use MAX_HEADER for headroom reserve in output pathDaniel Borkmann2015-01-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | commit 9772b54c55266ce80c639a80aa68eeb908f8ecf5 upstream. To accomodate for enough headroom for tunnels, use MAX_HEADER instead of LL_MAX_HEADER. Robert reported that he has hit after roughly 40hrs of trinity an skb_under_panic() via SCTP output path (see reference). I couldn't reproduce it from here, but not using MAX_HEADER as elsewhere in other protocols might be one possible cause for this. In any case, it looks like accounting on chunks themself seems to look good as the skb already passed the SCTP output path and did not hit any skb_over_panic(). Given tunneling was enabled in his .config, the headroom would have been expanded by MAX_HEADER in this case. Reported-by: Robert Święcki <robert@swiecki.net> Reference: https://lkml.org/lkml/2014/12/1/507 Fixes: 594ccc14dfe4d ("[SCTP] Replace incorrect use of dev_alloc_skb with alloc_skb in sctp_packet_transmit().") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix memory leak in auth key managementDaniel Borkmann2015-01-011-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 4184b2a79a7612a9272ce20d639934584a1f3786 upstream. A very minimal and simple user space application allocating an SCTP socket, setting SCTP_AUTH_KEY setsockopt(2) on it and then closing the socket again will leak the memory containing the authentication key from user space: unreferenced object 0xffff8800837047c0 (size 16): comm "a.out", pid 2789, jiffies 4296954322 (age 192.258s) hex dump (first 16 bytes): 01 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff816d7e8e>] kmemleak_alloc+0x4e/0xb0 [<ffffffff811c88d8>] __kmalloc+0xe8/0x270 [<ffffffffa0870c23>] sctp_auth_create_key+0x23/0x50 [sctp] [<ffffffffa08718b1>] sctp_auth_set_key+0xa1/0x140 [sctp] [<ffffffffa086b383>] sctp_setsockopt+0xd03/0x1180 [sctp] [<ffffffff815bfd94>] sock_common_setsockopt+0x14/0x20 [<ffffffff815beb61>] SyS_setsockopt+0x71/0xd0 [<ffffffff816e58a9>] system_call_fastpath+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff This is bad because of two things, we can bring down a machine from user space when auth_enable=1, but also we would leave security sensitive keying material in memory without clearing it after use. The issue is that sctp_auth_create_key() already sets the refcount to 1, but after allocation sctp_auth_set_key() does an additional refcount on it, and thus leaving it around when we free the socket. Fixes: 65b07e5d0d0 ("[SCTP]: API updates to suport SCTP-AUTH extensions.") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix NULL pointer dereference in af->from_addr_param on malformed ↵Daniel Borkmann2015-01-011-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | packet commit e40607cbe270a9e8360907cb1e62ddf0736e4864 upstream. An SCTP server doing ASCONF will panic on malformed INIT ping-of-death in the form of: ------------ INIT[PARAM: SET_PRIMARY_IP] ------------> While the INIT chunk parameter verification dissects through many things in order to detect malformed input, it misses to actually check parameters inside of parameters. E.g. RFC5061, section 4.2.4 proposes a 'set primary IP address' parameter in ASCONF, which has as a subparameter an address parameter. So an attacker may send a parameter type other than SCTP_PARAM_IPV4_ADDRESS or SCTP_PARAM_IPV6_ADDRESS, param_type2af() will subsequently return 0 and thus sctp_get_af_specific() returns NULL, too, which we then happily dereference unconditionally through af->from_addr_param(). The trace for the log: BUG: unable to handle kernel NULL pointer dereference at 0000000000000078 IP: [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp] PGD 0 Oops: 0000 [#1] SMP [...] Pid: 0, comm: swapper Not tainted 2.6.32-504.el6.x86_64 #1 Bochs Bochs RIP: 0010:[<ffffffffa01e9c62>] [<ffffffffa01e9c62>] sctp_process_init+0x492/0x990 [sctp] [...] Call Trace: <IRQ> [<ffffffffa01f2add>] ? sctp_bind_addr_copy+0x5d/0xe0 [sctp] [<ffffffffa01e1fcb>] sctp_sf_do_5_1B_init+0x21b/0x340 [sctp] [<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp] [<ffffffffa01e5c09>] ? sctp_endpoint_lookup_assoc+0xc9/0xf0 [sctp] [<ffffffffa01e61f6>] sctp_endpoint_bh_rcv+0x116/0x230 [sctp] [<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp] [<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp] [<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter] [<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0 [<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0 [<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120 [<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0 [...] A minimal way to address this is to check for NULL as we do on all other such occasions where we know sctp_get_af_specific() could possibly return with NULL. Fixes: d6de3097592b ("[SCTP]: Add the handling of "Set Primary IP Address" parameter to INIT") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix remote memory pressure from excessive queueingDaniel Borkmann2014-11-052-26/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 26b87c7881006311828bb0ab271a551a62dcceb4 upstream. This scenario is not limited to ASCONF, just taken as one example triggering the issue. When receiving ASCONF probes in the form of ... -------------- INIT[ASCONF; ASCONF_ACK] -------------> <----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------ -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- ---- ASCONF_a; [ASCONF_b; ...; ASCONF_n;] JUNK ------> [...] ---- ASCONF_m; [ASCONF_o; ...; ASCONF_z;] JUNK ------> ... where ASCONF_a, ASCONF_b, ..., ASCONF_z are good-formed ASCONFs and have increasing serial numbers, we process such ASCONF chunk(s) marked with !end_of_packet and !singleton, since we have not yet reached the SCTP packet end. SCTP does only do verification on a chunk by chunk basis, as an SCTP packet is nothing more than just a container of a stream of chunks which it eats up one by one. We could run into the case that we receive a packet with a malformed tail, above marked as trailing JUNK. All previous chunks are here goodformed, so the stack will eat up all previous chunks up to this point. In case JUNK does not fit into a chunk header and there are no more other chunks in the input queue, or in case JUNK contains a garbage chunk header, but the encoded chunk length would exceed the skb tail, or we came here from an entirely different scenario and the chunk has pdiscard=1 mark (without having had a flush point), it will happen, that we will excessively queue up the association's output queue (a correct final chunk may then turn it into a response flood when flushing the queue ;)): I ran a simple script with incremental ASCONF serial numbers and could see the server side consuming excessive amount of RAM [before/after: up to 2GB and more]. The issue at heart is that the chunk train basically ends with !end_of_packet and !singleton markers and since commit 2e3216cd54b1 ("sctp: Follow security requirement of responding with 1 packet") therefore preventing an output queue flush point in sctp_do_sm() -> sctp_cmd_interpreter() on the input chunk (chunk = event_arg) even though local_cork is set, but its precedence has changed since then. In the normal case, the last chunk with end_of_packet=1 would trigger the queue flush to accommodate possible outgoing bundling. In the input queue, sctp_inq_pop() seems to do the right thing in terms of discarding invalid chunks. So, above JUNK will not enter the state machine and instead be released and exit the sctp_assoc_bh_rcv() chunk processing loop. It's simply the flush point being missing at loop exit. Adding a try-flush approach on the output queue might not work as the underlying infrastructure might be long gone at this point due to the side-effect interpreter run. One possibility, albeit a bit of a kludge, would be to defer invalid chunk freeing into the state machine in order to possibly trigger packet discards and thus indirectly a queue flush on error. It would surely be better to discard chunks as in the current, perhaps better controlled environment, but going back and forth, it's simply architecturally not possible. I tried various trailing JUNK attack cases and it seems to look good now. Joint work with Vlad Yasevich. Fixes: 2e3216cd54b1 ("sctp: Follow security requirement of responding with 1 packet") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix panic on duplicate ASCONF chunksDaniel Borkmann2014-11-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit b69040d8e39f20d5215a03502a8e8b4c6ab78395 upstream. When receiving a e.g. semi-good formed connection scan in the form of ... -------------- INIT[ASCONF; ASCONF_ACK] -------------> <----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------ -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- ---------------- ASCONF_a; ASCONF_b -----------------> ... where ASCONF_a equals ASCONF_b chunk (at least both serials need to be equal), we panic an SCTP server! The problem is that good-formed ASCONF chunks that we reply with ASCONF_ACK chunks are cached per serial. Thus, when we receive a same ASCONF chunk twice (e.g. through a lost ASCONF_ACK), we do not need to process them again on the server side (that was the idea, also proposed in the RFC). Instead, we know it was cached and we just resend the cached chunk instead. So far, so good. Where things get nasty is in SCTP's side effect interpreter, that is, sctp_cmd_interpreter(): While incoming ASCONF_a (chunk = event_arg) is being marked !end_of_packet and !singleton, and we have an association context, we do not flush the outqueue the first time after processing the ASCONF_ACK singleton chunk via SCTP_CMD_REPLY. Instead, we keep it queued up, although we set local_cork to 1. Commit 2e3216cd54b1 changed the precedence, so that as long as we get bundled, incoming chunks we try possible bundling on outgoing queue as well. Before this commit, we would just flush the output queue. Now, while ASCONF_a's ASCONF_ACK sits in the corked outq, we continue to process the same ASCONF_b chunk from the packet. As we have cached the previous ASCONF_ACK, we find it, grab it and do another SCTP_CMD_REPLY command on it. So, effectively, we rip the chunk->list pointers and requeue the same ASCONF_ACK chunk another time. Since we process ASCONF_b, it's correctly marked with end_of_packet and we enforce an uncork, and thus flush, thus crashing the kernel. Fix it by testing if the ASCONF_ACK is currently pending and if that is the case, do not requeue it. When flushing the output queue we may relink the chunk for preparing an outgoing packet, but eventually unlink it when it's copied into the skb right before transmission. Joint work with Vlad Yasevich. Fixes: 2e3216cd54b1 ("sctp: Follow security requirement of responding with 1 packet") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix skb_over_panic when receiving malformed ASCONF chunksDaniel Borkmann2014-11-052-60/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 9de7922bc709eee2f609cd01d98aaedc4cf5ea74 upstream. Commit 6f4c618ddb0 ("SCTP : Add paramters validity check for ASCONF chunk") added basic verification of ASCONF chunks, however, it is still possible to remotely crash a server by sending a special crafted ASCONF chunk, even up to pre 2.6.12 kernels: skb_over_panic: text:ffffffffa01ea1c3 len:31056 put:30768 head:ffff88011bd81800 data:ffff88011bd81800 tail:0x7950 end:0x440 dev:<NULL> ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:129! [...] Call Trace: <IRQ> [<ffffffff8144fb1c>] skb_put+0x5c/0x70 [<ffffffffa01ea1c3>] sctp_addto_chunk+0x63/0xd0 [sctp] [<ffffffffa01eadaf>] sctp_process_asconf+0x1af/0x540 [sctp] [<ffffffff8152d025>] ? _read_unlock_bh+0x15/0x20 [<ffffffffa01e0038>] sctp_sf_do_asconf+0x168/0x240 [sctp] [<ffffffffa01e3751>] sctp_do_sm+0x71/0x1210 [sctp] [<ffffffff8147645d>] ? fib_rules_lookup+0xad/0xf0 [<ffffffffa01e6b22>] ? sctp_cmp_addr_exact+0x32/0x40 [sctp] [<ffffffffa01e8393>] sctp_assoc_bh_rcv+0xd3/0x180 [sctp] [<ffffffffa01ee986>] sctp_inq_push+0x56/0x80 [sctp] [<ffffffffa01fcc42>] sctp_rcv+0x982/0xa10 [sctp] [<ffffffffa01d5123>] ? ipt_local_in_hook+0x23/0x28 [iptable_filter] [<ffffffff8148bdc9>] ? nf_iterate+0x69/0xb0 [<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0 [<ffffffff8148bf86>] ? nf_hook_slow+0x76/0x120 [<ffffffff81496d10>] ? ip_local_deliver_finish+0x0/0x2d0 [<ffffffff81496ded>] ip_local_deliver_finish+0xdd/0x2d0 [<ffffffff81497078>] ip_local_deliver+0x98/0xa0 [<ffffffff8149653d>] ip_rcv_finish+0x12d/0x440 [<ffffffff81496ac5>] ip_rcv+0x275/0x350 [<ffffffff8145c88b>] __netif_receive_skb+0x4ab/0x750 [<ffffffff81460588>] netif_receive_skb+0x58/0x60 This can be triggered e.g., through a simple scripted nmap connection scan injecting the chunk after the handshake, for example, ... -------------- INIT[ASCONF; ASCONF_ACK] -------------> <----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------ -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- ------------------ ASCONF; UNKNOWN ------------------> ... where ASCONF chunk of length 280 contains 2 parameters ... 1) Add IP address parameter (param length: 16) 2) Add/del IP address parameter (param length: 255) ... followed by an UNKNOWN chunk of e.g. 4 bytes. Here, the Address Parameter in the ASCONF chunk is even missing, too. This is just an example and similarly-crafted ASCONF chunks could be used just as well. The ASCONF chunk passes through sctp_verify_asconf() as all parameters passed sanity checks, and after walking, we ended up successfully at the chunk end boundary, and thus may invoke sctp_process_asconf(). Parameter walking is done with WORD_ROUND() to take padding into account. In sctp_process_asconf()'s TLV processing, we may fail in sctp_process_asconf_param() e.g., due to removal of the IP address that is also the source address of the packet containing the ASCONF chunk, and thus we need to add all TLVs after the failure to our ASCONF response to remote via helper function sctp_add_asconf_response(), which basically invokes a sctp_addto_chunk() adding the error parameters to the given skb. When walking to the next parameter this time, we proceed with ... length = ntohs(asconf_param->param_hdr.length); asconf_param = (void *)asconf_param + length; ... instead of the WORD_ROUND()'ed length, thus resulting here in an off-by-one that leads to reading the follow-up garbage parameter length of 12336, and thus throwing an skb_over_panic for the reply when trying to sctp_addto_chunk() next time, which implicitly calls the skb_put() with that length. Fix it by using sctp_walk_params() [ which is also used in INIT parameter processing ] macro in the verification *and* in ASCONF processing: it will make sure we don't spill over, that we walk parameters WORD_ROUND()'ed. Moreover, we're being more defensive and guard against unknown parameter types and missized addresses. Joint work with Vlad Yasevich. Fixes: b896b82be4ae ("[SCTP] ADDIP: Support for processing incoming ASCONF_ACK chunks.") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> [bwh: Backported to 3.2: - Adjust context - sctp_sf_violation_paramlen() doesn't take a struct net * parameter] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: fix possible seqlock seadlock in sctp_packet_transmit()Eric Dumazet2014-09-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 757efd32d5ce31f67193cc0e6a56e4dffcc42fb1 ] Dave reported following splat, caused by improper use of IP_INC_STATS_BH() in process context. BUG: using __this_cpu_add() in preemptible [00000000] code: trinity-c117/14551 caller is __this_cpu_preempt_check+0x13/0x20 CPU: 3 PID: 14551 Comm: trinity-c117 Not tainted 3.16.0+ #33 ffffffff9ec898f0 0000000047ea7e23 ffff88022d32f7f0 ffffffff9e7ee207 0000000000000003 ffff88022d32f818 ffffffff9e397eaa ffff88023ee70b40 ffff88022d32f970 ffff8801c026d580 ffff88022d32f828 ffffffff9e397ee3 Call Trace: [<ffffffff9e7ee207>] dump_stack+0x4e/0x7a [<ffffffff9e397eaa>] check_preemption_disabled+0xfa/0x100 [<ffffffff9e397ee3>] __this_cpu_preempt_check+0x13/0x20 [<ffffffffc0839872>] sctp_packet_transmit+0x692/0x710 [sctp] [<ffffffffc082a7f2>] sctp_outq_flush+0x2a2/0xc30 [sctp] [<ffffffff9e0d985c>] ? mark_held_locks+0x7c/0xb0 [<ffffffff9e7f8c6d>] ? _raw_spin_unlock_irqrestore+0x5d/0x80 [<ffffffffc082b99a>] sctp_outq_uncork+0x1a/0x20 [sctp] [<ffffffffc081e112>] sctp_cmd_interpreter.isra.23+0x1142/0x13f0 [sctp] [<ffffffffc081c86b>] sctp_do_sm+0xdb/0x330 [sctp] [<ffffffff9e0b8f1b>] ? preempt_count_sub+0xab/0x100 [<ffffffffc083b350>] ? sctp_cname+0x70/0x70 [sctp] [<ffffffffc08389ca>] sctp_primitive_ASSOCIATE+0x3a/0x50 [sctp] [<ffffffffc083358f>] sctp_sendmsg+0x88f/0xe30 [sctp] [<ffffffff9e0d673a>] ? lock_release_holdtime.part.28+0x9a/0x160 [<ffffffff9e0d62ce>] ? put_lock_stats.isra.27+0xe/0x30 [<ffffffff9e73b624>] inet_sendmsg+0x104/0x220 [<ffffffff9e73b525>] ? inet_sendmsg+0x5/0x220 [<ffffffff9e68ac4e>] sock_sendmsg+0x9e/0xe0 [<ffffffff9e1c0c09>] ? might_fault+0xb9/0xc0 [<ffffffff9e1c0bae>] ? might_fault+0x5e/0xc0 [<ffffffff9e68b234>] SYSC_sendto+0x124/0x1c0 [<ffffffff9e0136b0>] ? syscall_trace_enter+0x250/0x330 [<ffffffff9e68c3ce>] SyS_sendto+0xe/0x10 [<ffffffff9e7f9be4>] tracesys+0xdd/0xe2 This is a followup of commits f1d8cba61c3c4b ("inet: fix possible seqlock deadlocks") and 7f88c6b23afbd315 ("ipv6: fix possible seqlock deadlock in ip6_finish_output2") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Reported-by: Dave Jones <davej@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: inherit auth_capable on INIT collisionsDaniel Borkmann2014-09-131-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1be9a950c646c9092fb3618197f7b6bfb50e82aa ] Jason reported an oops caused by SCTP on his ARM machine with SCTP authentication enabled: Internal error: Oops: 17 [#1] ARM CPU: 0 PID: 104 Comm: sctp-test Not tainted 3.13.0-68744-g3632f30c9b20-dirty #1 task: c6eefa40 ti: c6f52000 task.ti: c6f52000 PC is at sctp_auth_calculate_hmac+0xc4/0x10c LR is at sg_init_table+0x20/0x38 pc : [<c024bb80>] lr : [<c00f32dc>] psr: 40000013 sp : c6f538e8 ip : 00000000 fp : c6f53924 r10: c6f50d80 r9 : 00000000 r8 : 00010000 r7 : 00000000 r6 : c7be4000 r5 : 00000000 r4 : c6f56254 r3 : c00c8170 r2 : 00000001 r1 : 00000008 r0 : c6f1e660 Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 0005397f Table: 06f28000 DAC: 00000015 Process sctp-test (pid: 104, stack limit = 0xc6f521c0) Stack: (0xc6f538e8 to 0xc6f54000) [...] Backtrace: [<c024babc>] (sctp_auth_calculate_hmac+0x0/0x10c) from [<c0249af8>] (sctp_packet_transmit+0x33c/0x5c8) [<c02497bc>] (sctp_packet_transmit+0x0/0x5c8) from [<c023e96c>] (sctp_outq_flush+0x7fc/0x844) [<c023e170>] (sctp_outq_flush+0x0/0x844) from [<c023ef78>] (sctp_outq_uncork+0x24/0x28) [<c023ef54>] (sctp_outq_uncork+0x0/0x28) from [<c0234364>] (sctp_side_effects+0x1134/0x1220) [<c0233230>] (sctp_side_effects+0x0/0x1220) from [<c02330b0>] (sctp_do_sm+0xac/0xd4) [<c0233004>] (sctp_do_sm+0x0/0xd4) from [<c023675c>] (sctp_assoc_bh_rcv+0x118/0x160) [<c0236644>] (sctp_assoc_bh_rcv+0x0/0x160) from [<c023d5bc>] (sctp_inq_push+0x6c/0x74) [<c023d550>] (sctp_inq_push+0x0/0x74) from [<c024a6b0>] (sctp_rcv+0x7d8/0x888) While we already had various kind of bugs in that area ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capable") and b14878ccb7fa ("net: sctp: cache auth_enable per endpoint"), this one is a bit of a different kind. Giving a bit more background on why SCTP authentication is needed can be found in RFC4895: SCTP uses 32-bit verification tags to protect itself against blind attackers. These values are not changed during the lifetime of an SCTP association. Looking at new SCTP extensions, there is the need to have a method of proving that an SCTP chunk(s) was really sent by the original peer that started the association and not by a malicious attacker. To cause this bug, we're triggering an INIT collision between peers; normal SCTP handshake where both sides intent to authenticate packets contains RANDOM; CHUNKS; HMAC-ALGO parameters that are being negotiated among peers: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- RFC4895 says that each endpoint therefore knows its own random number and the peer's random number *after* the association has been established. The local and peer's random number along with the shared key are then part of the secret used for calculating the HMAC in the AUTH chunk. Now, in our scenario, we have 2 threads with 1 non-blocking SEQ_PACKET socket each, setting up common shared SCTP_AUTH_KEY and SCTP_AUTH_ACTIVE_KEY properly, and each of them calling sctp_bindx(3), listen(2) and connect(2) against each other, thus the handshake looks similar to this, e.g.: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- <--------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------- -------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------> ... Since such collisions can also happen with verification tags, the RFC4895 for AUTH rather vaguely says under section 6.1: In case of INIT collision, the rules governing the handling of this Random Number follow the same pattern as those for the Verification Tag, as explained in Section 5.2.4 of RFC 2960 [5]. Therefore, each endpoint knows its own Random Number and the peer's Random Number after the association has been established. In RFC2960, section 5.2.4, we're eventually hitting Action B: B) In this case, both sides may be attempting to start an association at about the same time but the peer endpoint started its INIT after responding to the local endpoint's INIT. Thus it may have picked a new Verification Tag not being aware of the previous Tag it had sent this endpoint. The endpoint should stay in or enter the ESTABLISHED state but it MUST update its peer's Verification Tag from the State Cookie, stop any init or cookie timers that may running and send a COOKIE ACK. In other words, the handling of the Random parameter is the same as behavior for the Verification Tag as described in Action B of section 5.2.4. Looking at the code, we exactly hit the sctp_sf_do_dupcook_b() case which triggers an SCTP_CMD_UPDATE_ASSOC command to the side effect interpreter, and in fact it properly copies over peer_{random, hmacs, chunks} parameters from the newly created association to update the existing one. Also, the old asoc_shared_key is being released and based on the new params, sctp_auth_asoc_init_active_key() updated. However, the issue observed in this case is that the previous asoc->peer.auth_capable was 0, and has *not* been updated, so that instead of creating a new secret, we're doing an early return from the function sctp_auth_asoc_init_active_key() leaving asoc->asoc_shared_key as NULL. However, we now have to authenticate chunks from the updated chunk list (e.g. COOKIE-ACK). That in fact causes the server side when responding with ... <------------------ AUTH; COOKIE-ACK ----------------- ... to trigger a NULL pointer dereference, since in sctp_packet_transmit(), it discovers that an AUTH chunk is being queued for xmit, and thus it calls sctp_auth_calculate_hmac(). Since the asoc->active_key_id is still inherited from the endpoint, and the same as encoded into the chunk, it uses asoc->asoc_shared_key, which is still NULL, as an asoc_key and dereferences it in ... crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len) ... causing an oops. All this happens because sctp_make_cookie_ack() called with the *new* association has the peer.auth_capable=1 and therefore marks the chunk with auth=1 after checking sctp_auth_send_cid(), but it is *actually* sent later on over the then *updated* association's transport that didn't initialize its shared key due to peer.auth_capable=0. Since control chunks in that case are not sent by the temporary association which are scheduled for deletion, they are issued for xmit via SCTP_CMD_REPLY in the interpreter with the context of the *updated* association. peer.auth_capable was 0 in the updated association (which went from COOKIE_WAIT into ESTABLISHED state), since all previous processing that performed sctp_process_init() was being done on temporary associations, that we eventually throw away each time. The correct fix is to update to the new peer.auth_capable value as well in the collision case via sctp_assoc_update(), so that in case the collision migrated from 0 -> 1, sctp_auth_asoc_init_active_key() can properly recalculate the secret. This therefore fixes the observed server panic. Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing") Reported-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Tested-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix information leaks in ulpevent layerDaniel Borkmann2014-08-061-107/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8f2e5ae40ec193bc0a0ed99e95315c3eebca84ea ] While working on some other SCTP code, I noticed that some structures shared with user space are leaking uninitialized stack or heap buffer. In particular, struct sctp_sndrcvinfo has a 2 bytes hole between .sinfo_flags and .sinfo_ppid that remains unfilled by us in sctp_ulpevent_read_sndrcvinfo() when putting this into cmsg. But also struct sctp_remote_error contains a 2 bytes hole that we don't fill but place into a skb through skb_copy_expand() via sctp_ulpevent_make_remote_error(). Both structures are defined by the IETF in RFC6458: * Section 5.3.2. SCTP Header Information Structure: The sctp_sndrcvinfo structure is defined below: struct sctp_sndrcvinfo { uint16_t sinfo_stream; uint16_t sinfo_ssn; uint16_t sinfo_flags; <-- 2 bytes hole --> uint32_t sinfo_ppid; uint32_t sinfo_context; uint32_t sinfo_timetolive; uint32_t sinfo_tsn; uint32_t sinfo_cumtsn; sctp_assoc_t sinfo_assoc_id; }; * 6.1.3. SCTP_REMOTE_ERROR: A remote peer may send an Operation Error message to its peer. This message indicates a variety of error conditions on an association. The entire ERROR chunk as it appears on the wire is included in an SCTP_REMOTE_ERROR event. Please refer to the SCTP specification [RFC4960] and any extensions for a list of possible error formats. An SCTP error notification has the following format: struct sctp_remote_error { uint16_t sre_type; uint16_t sre_flags; uint32_t sre_length; uint16_t sre_error; <-- 2 bytes hole --> sctp_assoc_t sre_assoc_id; uint8_t sre_data[]; }; Fix this by setting both to 0 before filling them out. We also have other structures shared between user and kernel space in SCTP that contains holes (e.g. struct sctp_paddrthlds), but we copy that buffer over from user space first and thus don't need to care about it in that cases. While at it, we can also remove lengthy comments copied from the draft, instead, we update the comment with the correct RFC number where one can look it up. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Fix sk_ack_backlog wrap-around problemXufeng Zhang2014-07-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit d3217b15a19a4779c39b212358a5c71d725822ee ] Consider the scenario: For a TCP-style socket, while processing the COOKIE_ECHO chunk in sctp_sf_do_5_1D_ce(), after it has passed a series of sanity check, a new association would be created in sctp_unpack_cookie(), but afterwards, some processing maybe failed, and sctp_association_free() will be called to free the previously allocated association, in sctp_association_free(), sk_ack_backlog value is decremented for this socket, since the initial value for sk_ack_backlog is 0, after the decrement, it will be 65535, a wrap-around problem happens, and if we want to establish new associations afterward in the same socket, ABORT would be triggered since sctp deem the accept queue as full. Fix this issue by only decrementing sk_ack_backlog for associations in the endpoint's list. Fix-suggested-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: reset flowi4_oif parameter on route lookupXufeng Zhang2014-06-091-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 85350871317a5adb35519d9dc6fc9e80809d42ad ] commit 813b3b5db83 (ipv4: Use caller's on-stack flowi as-is in output route lookups.) introduces another regression which is very similar to the problem of commit e6b45241c (ipv4: reset flowi parameters on route connect) wants to fix: Before we call ip_route_output_key() in sctp_v4_get_dst() to get a dst that matches a bind address as the source address, we have already called this function previously and the flowi parameters have been initialized including flowi4_oif, so when we call this function again, the process in __ip_route_output_key() will be different because of the setting of flowi4_oif, and we'll get a networking device which corresponds to the inputted flowi4_oif as the output device, this is wrong because we'll never hit this place if the previously returned source address of dst match one of the bound addresses. To reproduce this problem, a vlan setting is enough: # ifconfig eth0 up # route del default # vconfig add eth0 2 # vconfig add eth0 3 # ifconfig eth0.2 10.0.1.14 netmask 255.255.255.0 # route add default gw 10.0.1.254 dev eth0.2 # ifconfig eth0.3 10.0.0.14 netmask 255.255.255.0 # ip rule add from 10.0.0.14 table 4 # ip route add table 4 default via 10.0.0.254 src 10.0.0.14 dev eth0.3 # sctp_darn -H 10.0.0.14 -P 36422 -h 10.1.4.134 -p 36422 -s -I You'll detect that all the flow are routed to eth0.2(10.0.1.254). Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com> Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix skb leakage in COOKIE ECHO path of chunk->auth_chunkDaniel Borkmann2014-04-302-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit c485658bae87faccd7aed540fd2ca3ab37992310 ] While working on ec0223ec48a9 ("net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capable"), we noticed that there's a skb memory leakage in the error path. Running the same reproducer as in ec0223ec48a9 and by unconditionally jumping to the error label (to simulate an error condition) in sctp_sf_do_5_1D_ce() receive path lets kmemleak detector bark about the unfreed chunk->auth_chunk skb clone: Unreferenced object 0xffff8800b8f3a000 (size 256): comm "softirq", pid 0, jiffies 4294769856 (age 110.757s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 89 ab 75 5e d4 01 58 13 00 00 00 00 00 00 00 00 ..u^..X......... backtrace: [<ffffffff816660be>] kmemleak_alloc+0x4e/0xb0 [<ffffffff8119f328>] kmem_cache_alloc+0xc8/0x210 [<ffffffff81566929>] skb_clone+0x49/0xb0 [<ffffffffa0467459>] sctp_endpoint_bh_rcv+0x1d9/0x230 [sctp] [<ffffffffa046fdbc>] sctp_inq_push+0x4c/0x70 [sctp] [<ffffffffa047e8de>] sctp_rcv+0x82e/0x9a0 [sctp] [<ffffffff815abd38>] ip_local_deliver_finish+0xa8/0x210 [<ffffffff815a64af>] nf_reinject+0xbf/0x180 [<ffffffffa04b4762>] nfqnl_recv_verdict+0x1d2/0x2b0 [nfnetlink_queue] [<ffffffffa04aa40b>] nfnetlink_rcv_msg+0x14b/0x250 [nfnetlink] [<ffffffff815a3269>] netlink_rcv_skb+0xa9/0xc0 [<ffffffffa04aa7cf>] nfnetlink_rcv+0x23f/0x408 [nfnetlink] [<ffffffff815a2bd8>] netlink_unicast+0x168/0x250 [<ffffffff815a2fa1>] netlink_sendmsg+0x2e1/0x3f0 [<ffffffff8155cc6b>] sock_sendmsg+0x8b/0xc0 [<ffffffff8155d449>] ___sys_sendmsg+0x369/0x380 What happens is that commit bbd0d59809f9 clones the skb containing the AUTH chunk in sctp_endpoint_bh_rcv() when having the edge case that an endpoint requires COOKIE-ECHO chunks to be authenticated: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- ------------------ AUTH; COOKIE-ECHO ----------------> <-------------------- COOKIE-ACK --------------------- When we enter sctp_sf_do_5_1D_ce() and before we actually get to the point where we process (and subsequently free) a non-NULL chunk->auth_chunk, we could hit the "goto nomem_init" path from an error condition and thus leave the cloned skb around w/o freeing it. The fix is to centrally free such clones in sctp_chunk_destroy() handler that is invoked from sctp_chunk_free() after all refs have dropped; and also move both kfree_skb(chunk->auth_chunk) there, so that chunk->auth_chunk is either NULL (since sctp_chunkify() allocs new chunks through kmem_cache_zalloc()) or non-NULL with a valid skb pointer. chunk->skb and chunk->auth_chunk are the only skbs in the sctp_chunk structure that need to be handeled. While at it, we should use consume_skb() for both. It is the same as dev_kfree_skb() but more appropriately named as we are not a device but a protocol. Also, this effectively replaces the kfree_skb() from both invocations into consume_skb(). Functions are the same only that kfree_skb() assumes that the frame was being dropped after a failure (e.g. for tools like drop monitor), usage of consume_skb() seems more appropriate in function sctp_chunk_destroy() though. Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <yasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capableDaniel Borkmann2014-04-021-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ec0223ec48a90cb605244b45f7c62de856403729 ] RFC4895 introduced AUTH chunks for SCTP; during the SCTP handshake RANDOM; CHUNKS; HMAC-ALGO are negotiated (CHUNKS being optional though): ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- A special case is when an endpoint requires COOKIE-ECHO chunks to be authenticated: ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ----------> <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] --------- ------------------ AUTH; COOKIE-ECHO ----------------> <-------------------- COOKIE-ACK --------------------- RFC4895, section 6.3. Receiving Authenticated Chunks says: The receiver MUST use the HMAC algorithm indicated in the HMAC Identifier field. If this algorithm was not specified by the receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk during association setup, the AUTH chunk and all the chunks after it MUST be discarded and an ERROR chunk SHOULD be sent with the error cause defined in Section 4.1. [...] If no endpoint pair shared key has been configured for that Shared Key Identifier, all authenticated chunks MUST be silently discarded. [...] When an endpoint requires COOKIE-ECHO chunks to be authenticated, some special procedures have to be followed because the reception of a COOKIE-ECHO chunk might result in the creation of an SCTP association. If a packet arrives containing an AUTH chunk as a first chunk, a COOKIE-ECHO chunk as the second chunk, and possibly more chunks after them, and the receiver does not have an STCB for that packet, then authentication is based on the contents of the COOKIE-ECHO chunk. In this situation, the receiver MUST authenticate the chunks in the packet by using the RANDOM parameters, CHUNKS parameters and HMAC_ALGO parameters obtained from the COOKIE-ECHO chunk, and possibly a local shared secret as inputs to the authentication procedure specified in Section 6.3. If authentication fails, then the packet is discarded. If the authentication is successful, the COOKIE-ECHO and all the chunks after the COOKIE-ECHO MUST be processed. If the receiver has an STCB, it MUST process the AUTH chunk as described above using the STCB from the existing association to authenticate the COOKIE-ECHO chunk and all the chunks after it. [...] Commit bbd0d59809f9 introduced the possibility to receive and verification of AUTH chunk, including the edge case for authenticated COOKIE-ECHO. On reception of COOKIE-ECHO, the function sctp_sf_do_5_1D_ce() handles processing, unpacks and creates a new association if it passed sanity checks and also tests for authentication chunks being present. After a new association has been processed, it invokes sctp_process_init() on the new association and walks through the parameter list it received from the INIT chunk. It checks SCTP_PARAM_RANDOM, SCTP_PARAM_HMAC_ALGO and SCTP_PARAM_CHUNKS, and copies them into asoc->peer meta data (peer_random, peer_hmacs, peer_chunks) in case sysctl -w net.sctp.auth_enable=1 is set. If in INIT's SCTP_PARAM_SUPPORTED_EXT parameter SCTP_CID_AUTH is set, peer_random != NULL and peer_hmacs != NULL the peer is to be assumed asoc->peer.auth_capable=1, in any other case asoc->peer.auth_capable=0. Now, if in sctp_sf_do_5_1D_ce() chunk->auth_chunk is available, we set up a fake auth chunk and pass that on to sctp_sf_authenticate(), which at latest in sctp_auth_calculate_hmac() reliably dereferences a NULL pointer at position 0..0008 when setting up the crypto key in crypto_hash_setkey() by using asoc->asoc_shared_key that is NULL as condition key_id == asoc->active_key_id is true if the AUTH chunk was injected correctly from remote. This happens no matter what net.sctp.auth_enable sysctl says. The fix is to check for net->sctp.auth_enable and for asoc->peer.auth_capable before doing any operations like sctp_sf_authenticate() as no key is activated in sctp_auth_asoc_init_active_key() for each case. Now as RFC4895 section 6.3 states that if the used HMAC-ALGO passed from the INIT chunk was not used in the AUTH chunk, we SHOULD send an error; however in this case it would be better to just silently discard such a maliciously prepared handshake as we didn't even receive a parameter at all. Also, as our endpoint has no shared key configured, section 6.3 says that MUST silently discard, which we are doing from now onwards. Before calling sctp_sf_pdiscard(), we need not only to free the association, but also the chunk->auth_chunk skb, as commit bbd0d59809f9 created a skb clone in that case. I have tested this locally by using netfilter's nfqueue and re-injecting packets into the local stack after maliciously modifying the INIT chunk (removing RANDOM; HMAC-ALGO param) and the SCTP packet containing the COOKIE_ECHO (injecting AUTH chunk before COOKIE_ECHO). Fixed with this patch applied. Fixes: bbd0d59809f9 ("[SCTP]: Implement the receive and verification of AUTH chunk") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Vlad Yasevich <yasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix sctp_connectx abi for ia32 emulation/compat modeDaniel Borkmann2014-04-021-9/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit ffd5939381c609056b33b7585fb05a77b4c695f3 ] SCTP's sctp_connectx() abi breaks for 64bit kernels compiled with 32bit emulation (e.g. ia32 emulation or x86_x32). Due to internal usage of 'struct sctp_getaddrs_old' which includes a struct sockaddr pointer, sizeof(param) check will always fail in kernel as the structure in 64bit kernel space is 4bytes larger than for user binaries compiled in 32bit mode. Thus, applications making use of sctp_connectx() won't be able to run under such circumstances. Introduce a compat interface in the kernel to deal with such situations by using a 'struct compat_sctp_getaddrs_old' structure where user data is copied into it, and then sucessively transformed into a 'struct sctp_getaddrs_old' structure with the help of compat_ptr(). That fixes sctp_connectx() abi without any changes needed in user space, and lets the SCTP test suite pass when compiled in 32bit and run on 64bit kernels. Fixes: f9c67811ebc0 ("sctp: Fix regression introduced by new sctp_connectx api") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Perform software checksum if packet has to be fragmented.Vlad Yasevich2013-11-281-1/+1
| | | | | | | | | | | | | | | | | | [ Upstream commit d2dbbba77e95dff4b4f901fee236fef6d9552072 ] IP/IPv6 fragmentation knows how to compute only TCP/UDP checksum. This causes problems if SCTP packets has to be fragmented and ipsummed has been set to PARTIAL due to checksum offload support. This condition can happen when retransmitting after MTU discover, or when INIT or other control chunks are larger then MTU. Check for the rare fragmentation condition in SCTP and use software checksum calculation in this case. CC: Fan Du <fan.du@windriver.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Use software crc32 checksum when xfrm transform will happen.Fan Du2013-11-281-1/+2
| | | | | | | | | | | | | | | | | | [ Upstream commit 27127a82561a2a3ed955ce207048e1b066a80a2a ] igb/ixgbe have hardware sctp checksum support, when this feature is enabled and also IPsec is armed to protect sctp traffic, ugly things happened as xfrm_output checks CHECKSUM_PARTIAL to do checksum operation(sum every thing up and pack the 16bits result in the checksum field). The result is fail establishment of sctp communication. Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Fan Du <fan.du@windriver.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* Revert "sctp: fix call to SCTP_CMD_PROCESS_SACK in sctp_cmd_interpreter()"Ben Hutchings2013-10-261-2/+1
| | | | | | | | | | This reverts commit de77b7955c3985ca95f64af3cb10557eb17eacee, which was commit f6e80abeab928b7c47cc1fbf53df13b4398a2bec upstream. This fix was only appropriate for Linux 3.7 onward, and introduced a regression when applied to earlier versions. Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix ipv6 ipsec encryption bug in sctp_v6_xmitDaniel Borkmann2013-10-261-29/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 95ee62083cb6453e056562d91f597552021e6ae7 ] Alan Chester reported an issue with IPv6 on SCTP that IPsec traffic is not being encrypted, whereas on IPv4 it is. Setting up an AH + ESP transport does not seem to have the desired effect: SCTP + IPv4: 22:14:20.809645 IP (tos 0x2,ECT(0), ttl 64, id 0, offset 0, flags [DF], proto AH (51), length 116) 192.168.0.2 > 192.168.0.5: AH(spi=0x00000042,sumlen=16,seq=0x1): ESP(spi=0x00000044,seq=0x1), length 72 22:14:20.813270 IP (tos 0x2,ECT(0), ttl 64, id 0, offset 0, flags [DF], proto AH (51), length 340) 192.168.0.5 > 192.168.0.2: AH(spi=0x00000043,sumlen=16,seq=0x1): SCTP + IPv6: 22:31:19.215029 IP6 (class 0x02, hlim 64, next-header SCTP (132) payload length: 364) fe80::222:15ff:fe87:7fc.3333 > fe80::92e6:baff:fe0d:5a54.36767: sctp 1) [INIT ACK] [init tag: 747759530] [rwnd: 62464] [OS: 10] [MIS: 10] Moreover, Alan says: This problem was seen with both Racoon and Racoon2. Other people have seen this with OpenSwan. When IPsec is configured to encrypt all upper layer protocols the SCTP connection does not initialize. After using Wireshark to follow packets, this is because the SCTP packet leaves Box A unencrypted and Box B believes all upper layer protocols are to be encrypted so it drops this packet, causing the SCTP connection to fail to initialize. When IPsec is configured to encrypt just SCTP, the SCTP packets are observed unencrypted. In fact, using `socat sctp6-listen:3333 -` on one end and transferring "plaintext" string on the other end, results in cleartext on the wire where SCTP eventually does not report any errors, thus in the latter case that Alan reports, the non-paranoid user might think he's communicating over an encrypted transport on SCTP although he's not (tcpdump ... -X): ... 0x0030: 5d70 8e1a 0003 001a 177d eb6c 0000 0000 ]p.......}.l.... 0x0040: 0000 0000 706c 6169 6e74 6578 740a 0000 ....plaintext... Only in /proc/net/xfrm_stat we can see XfrmInTmplMismatch increasing on the receiver side. Initial follow-up analysis from Alan's bug report was done by Alexey Dobriyan. Also thanks to Vlad Yasevich for feedback on this. SCTP has its own implementation of sctp_v6_xmit() not calling inet6_csk_xmit(). This has the implication that it probably never really got updated along with changes in inet6_csk_xmit() and therefore does not seem to invoke xfrm handlers. SCTP's IPv4 xmit however, properly calls ip_queue_xmit() to do the work. Since a call to inet6_csk_xmit() would solve this problem, but result in unecessary route lookups, let us just use the cached flowi6 instead that we got through sctp_v6_get_dst(). Since all SCTP packets are being sent through sctp_packet_transmit(), we do the route lookup / flow caching in sctp_transport_route(), hold it in tp->dst and skb_dst_set() right after that. If we would alter fl6->daddr in sctp_v6_xmit() to np->opt->srcrt, we possibly could run into the same effect of not having xfrm layer pick it up, hence, use fl6_update_dst() in sctp_v6_get_dst() instead to get the correct source routed dst entry, which we assign to the skb. Also source address routing example from 625034113 ("sctp: fix sctp to work with ipv6 source address routing") still works with this patch! Nevertheless, in RFC5095 it is actually 'recommended' to not use that anyway due to traffic amplification [1]. So it seems we're not supposed to do that anyway in sctp_v6_xmit(). Moreover, if we overwrite the flow destination here, the lower IPv6 layer will be unable to put the correct destination address into IP header, as routing header is added in ipv6_push_nfrag_opts() but then probably with wrong final destination. Things aside, result of this patch is that we do not have any XfrmInTmplMismatch increase plus on the wire with this patch it now looks like: SCTP + IPv6: 08:17:47.074080 IP6 2620:52:0:102f:7a2b:cbff:fe27:1b0a > 2620:52:0:102f:213:72ff:fe32:7eba: AH(spi=0x00005fb4,seq=0x1): ESP(spi=0x00005fb5,seq=0x1), length 72 08:17:47.074264 IP6 2620:52:0:102f:213:72ff:fe32:7eba > 2620:52:0:102f:7a2b:cbff:fe27:1b0a: AH(spi=0x00003d54,seq=0x1): ESP(spi=0x00003d55,seq=0x1), length 296 This fixes Kernel Bugzilla 24412. This security issue seems to be present since 2.6.18 kernels. Lets just hope some big passive adversary in the wild didn't have its fun with that. lksctp-tools IPv6 regression test suite passes as well with this patch. [1] http://www.secdev.org/conf/IPv6_RH_security-csw07.pdf Reported-by: Alan Chester <alan.chester@tekelec.com> Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix smatch warning in sctp_send_asconf_del_ipDaniel Borkmann2013-10-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 88362ad8f9a6cea787420b57cc27ccacef000dbe ] This was originally reported in [1] and posted by Neil Horman [2], he said: Fix up a missed null pointer check in the asconf code. If we don't find a local address, but we pass in an address length of more than 1, we may dereference a NULL laddr pointer. Currently this can't happen, as the only users of the function pass in the value 1 as the addrcnt parameter, but its not hot path, and it doesn't hurt to check for NULL should that ever be the case. The callpath from sctp_asconf_mgmt() looks okay. But this could be triggered from sctp_setsockopt_bindx() call with SCTP_BINDX_REM_ADDR and addrcnt > 1 while passing all possible addresses from the bind list to SCTP_BINDX_REM_ADDR so that we do *not* find a single address in the association's bind address list that is not in the packed array of addresses. If this happens when we have an established association with ASCONF-capable peers, then we could get a NULL pointer dereference as we only check for laddr == NULL && addrcnt == 1 and call later sctp_make_asconf_update_ip() with NULL laddr. BUT: this actually won't happen as sctp_bindx_rem() will catch such a case and return with an error earlier. As this is incredably unintuitive and error prone, add a check to catch at least future bugs here. As Neil says, its not hot path. Introduced by 8a07eb0a5 ("sctp: Add ASCONF operation on the single-homed host"). [1] http://www.spinics.net/lists/linux-sctp/msg02132.html [2] http://www.spinics.net/lists/linux-sctp/msg02133.html Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Michio Honda <micchie@sfc.wide.ad.jp> Acked-By: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: fully initialize sctp_outq in sctp_outq_initNeil Horman2013-09-101-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit c5c7774d7eb4397891edca9ebdf750ba90977a69 ] In commit 2f94aabd9f6c925d77aecb3ff020f1cc12ed8f86 (refactor sctp_outq_teardown to insure proper re-initalization) we modified sctp_outq_teardown to use sctp_outq_init to fully re-initalize the outq structure. Steve West recently asked me why I removed the q->error = 0 initalization from sctp_outq_teardown. I did so because I was operating under the impression that sctp_outq_init would properly initalize that value for us, but it doesn't. sctp_outq_init operates under the assumption that the outq struct is all 0's (as it is when called from sctp_association_init), but using it in __sctp_outq_teardown violates that assumption. We should do a memset in sctp_outq_init to ensure that the entire structure is in a known state there instead. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: "West, Steve (NSN - US/Fort Worth)" <steve.west@nsn.com> CC: Vlad Yasevich <vyasevich@gmail.com> CC: netdev@vger.kernel.org CC: davem@davemloft.net Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: fix NULL pointer dereference in socket destructionDaniel Borkmann2013-06-291-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 1abd165ed757db1afdefaac0a4bc8a70f97d258c ] While stress testing sctp sockets, I hit the following panic: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: [<ffffffffa0490c4e>] sctp_endpoint_free+0xe/0x40 [sctp] PGD 7cead067 PUD 7ce76067 PMD 0 Oops: 0000 [#1] SMP Modules linked in: sctp(F) libcrc32c(F) [...] CPU: 7 PID: 2950 Comm: acc Tainted: GF 3.10.0-rc2+ #1 Hardware name: Dell Inc. PowerEdge T410/0H19HD, BIOS 1.6.3 02/01/2011 task: ffff88007ce0e0c0 ti: ffff88007b568000 task.ti: ffff88007b568000 RIP: 0010:[<ffffffffa0490c4e>] [<ffffffffa0490c4e>] sctp_endpoint_free+0xe/0x40 [sctp] RSP: 0018:ffff88007b569e08 EFLAGS: 00010292 RAX: 0000000000000000 RBX: ffff88007db78a00 RCX: dead000000200200 RDX: ffffffffa049fdb0 RSI: ffff8800379baf38 RDI: 0000000000000000 RBP: ffff88007b569e18 R08: ffff88007c230da0 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff880077990d00 R14: 0000000000000084 R15: ffff88007db78a00 FS: 00007fc18ab61700(0000) GS:ffff88007fc60000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000020 CR3: 000000007cf9d000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff88007b569e38 ffff88007db78a00 ffff88007b569e38 ffffffffa049fded ffffffff81abf0c0 ffff88007db78a00 ffff88007b569e58 ffffffff8145b60e 0000000000000000 0000000000000000 ffff88007b569eb8 ffffffff814df36e Call Trace: [<ffffffffa049fded>] sctp_destroy_sock+0x3d/0x80 [sctp] [<ffffffff8145b60e>] sk_common_release+0x1e/0xf0 [<ffffffff814df36e>] inet_create+0x2ae/0x350 [<ffffffff81455a6f>] __sock_create+0x11f/0x240 [<ffffffff81455bf0>] sock_create+0x30/0x40 [<ffffffff8145696c>] SyS_socket+0x4c/0xc0 [<ffffffff815403be>] ? do_page_fault+0xe/0x10 [<ffffffff8153cb32>] ? page_fault+0x22/0x30 [<ffffffff81544e02>] system_call_fastpath+0x16/0x1b Code: 0c c9 c3 66 2e 0f 1f 84 00 00 00 00 00 e8 fb fe ff ff c9 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 53 48 83 ec 08 66 66 66 66 90 <48> 8b 47 20 48 89 fb c6 47 1c 01 c6 40 12 07 e8 9e 68 01 00 48 RIP [<ffffffffa0490c4e>] sctp_endpoint_free+0xe/0x40 [sctp] RSP <ffff88007b569e08> CR2: 0000000000000020 ---[ end trace e0d71ec1108c1dd9 ]--- I did not hit this with the lksctp-tools functional tests, but with a small, multi-threaded test program, that heavily allocates, binds, listens and waits in accept on sctp sockets, and then randomly kills some of them (no need for an actual client in this case to hit this). Then, again, allocating, binding, etc, and then killing child processes. This panic then only occurs when ``echo 1 > /proc/sys/net/sctp/auth_enable'' is set. The cause for that is actually very simple: in sctp_endpoint_init() we enter the path of sctp_auth_init_hmacs(). There, we try to allocate our crypto transforms through crypto_alloc_hash(). In our scenario, it then can happen that crypto_alloc_hash() fails with -EINTR from crypto_larval_wait(), thus we bail out and release the socket via sk_common_release(), sctp_destroy_sock() and hit the NULL pointer dereference as soon as we try to access members in the endpoint during sctp_endpoint_free(), since endpoint at that time is still NULL. Now, if we have that case, we do not need to do any cleanup work and just leave the destruction handler. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: sctp_auth_key_put: use kzfree instead of kfreeDaniel Borkmann2013-05-131-1/+1
| | | | | | | | | | | | | | [ Upstream commit 586c31f3bf04c290dc0a0de7fc91d20aa9a5ee53 ] For sensitive data like keying material, it is common practice to zero out keys before returning the memory back to the allocator. Thus, use kzfree instead of kfree. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: don't break the loop while meeting the active_path so as to find the ↵Xufeng Zhang2013-03-271-1/+1
| | | | | | | | | | | | | | | | | | matched transport [ Upstream commit 2317f449af30073cfa6ec8352e4a65a89e357bdd ] sctp_assoc_lookup_tsn() function searchs which transport a certain TSN was sent on, if not found in the active_path transport, then go search all the other transports in the peer's transport_addr_list, however, we should continue to the next entry rather than break the loop when meet the active_path transport. Signed-off-by: Xufeng Zhang <xufeng.zhang@windriver.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Use correct sideffect command in duplicate cookie handlingVlad Yasevich2013-03-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit f2815633504b442ca0b0605c16bf3d88a3a0fcea ] When SCTP is done processing a duplicate cookie chunk, it tries to delete a newly created association. For that, it has to set the right association for the side-effect processing to work. However, when it uses the SCTP_CMD_NEW_ASOC command, that performs more work then really needed (like hashing the associationa and assigning it an id) and there is no point to do that only to delete the association as a next step. In fact, it also creates an impossible condition where an association may be found by the getsockopt() call, and that association is empty. This causes a crash in some sctp getsockopts. The solution is rather simple. We simply use SCTP_CMD_SET_ASOC command that doesn't have all the overhead and does exactly what we need. Reported-by: Karl Heiss <kheiss@gmail.com> Tested-by: Karl Heiss <kheiss@gmail.com> CC: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: sctp_endpoint_free: zero out secret key dataDaniel Borkmann2013-02-201-0/+5
| | | | | | | | | | | | | [ Upstream commit b5c37fe6e24eec194bb29d22fdd55d73bcc709bf ] On sctp_endpoint_destroy, previously used sensitive keying material should be zeroed out before the memory is returned, as we already do with e.g. auth keys when released. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* net: sctp: sctp_setsockopt_auth_key: use kzfree instead of kfreeDaniel Borkmann2013-02-201-1/+1
| | | | | | | | | | | | | | | [ Upstream commit 6ba542a291a5e558603ac51cda9bded347ce7627 ] In sctp_setsockopt_auth_key, we create a temporary copy of the user passed shared auth key for the endpoint or association and after internal setup, we free it right away. Since it's sensitive data, we should zero out the key before returning the memory back to the allocator. Thus, use kzfree instead of kfree, just as we do in sctp_auth_key_put(). Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: refactor sctp_outq_teardown to insure proper re-initalizationNeil Horman2013-02-201-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2f94aabd9f6c925d77aecb3ff020f1cc12ed8f86 ] Jamie Parsons reported a problem recently, in which the re-initalization of an association (The duplicate init case), resulted in a loss of receive window space. He tracked down the root cause to sctp_outq_teardown, which discarded all the data on an outq during a re-initalization of the corresponding association, but never reset the outq->outstanding_data field to zero. I wrote, and he tested this fix, which does a proper full re-initalization of the outq, fixing this problem, and hopefully future proofing us from simmilar issues down the road. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Jamie Parsons <Jamie.Parsons@metaswitch.com> Tested-by: Jamie Parsons <Jamie.Parsons@metaswitch.com> CC: Jamie Parsons <Jamie.Parsons@metaswitch.com> CC: Vlad Yasevich <vyasevich@gmail.com> CC: "David S. Miller" <davem@davemloft.net> CC: netdev@vger.kernel.org Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: fix -ENOMEM result with invalid user space pointer in sendto() syscallTommi Rantala2013-01-032-6/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 6e51fe7572590d8d86e93b547fab6693d305fd0d ] Consider the following program, that sets the second argument to the sendto() syscall incorrectly: #include <string.h> #include <arpa/inet.h> #include <sys/socket.h> int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } We get -ENOMEM: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 ENOMEM (Cannot allocate memory) Propagate the error code from sctp_user_addto_chunk(), so that we will tell user space what actually went wrong: $ strace -e sendto ./demo sendto(3, NULL, 1, 0, {sa_family=AF_INET, sin_port=htons(11111), sin_addr=inet_addr("127.0.0.1")}, 16) = -1 EFAULT (Bad address) Noticed while running Trinity (the syscall fuzzer). Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: fix memory leak in sctp_datamsg_from_user() when copy from user space ↵Tommi Rantala2013-01-031-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fails [ Upstream commit be364c8c0f17a3dd42707b5a090b318028538eb9 ] Trinity (the syscall fuzzer) discovered a memory leak in SCTP, reproducible e.g. with the sendto() syscall by passing invalid user space pointer in the second argument: #include <string.h> #include <arpa/inet.h> #include <sys/socket.h> int main(void) { int fd; struct sockaddr_in sa; fd = socket(AF_INET, SOCK_STREAM, 132 /*IPPROTO_SCTP*/); if (fd < 0) return 1; memset(&sa, 0, sizeof(sa)); sa.sin_family = AF_INET; sa.sin_addr.s_addr = inet_addr("127.0.0.1"); sa.sin_port = htons(11111); sendto(fd, NULL, 1, 0, (struct sockaddr *)&sa, sizeof(sa)); return 0; } As far as I can tell, the leak has been around since ~2003. Signed-off-by: Tommi Rantala <tt.rantala@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: fix call to SCTP_CMD_PROCESS_SACK in sctp_cmd_interpreter()Zijie Pan2012-11-161-1/+2
| | | | | | | | | | | | | [ Upstream commit f6e80abeab928b7c47cc1fbf53df13b4398a2bec ] Bug introduced by commit edfee0339e681a784ebacec7e8c2dc97dc6d2839 (sctp: check src addr when processing SACK to update transport state) Signed-off-by: Zijie Pan <zijie.pan@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Don't charge for data in sndbuf again when transmitting packetThomas Graf2012-10-101-1/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 4c3a5bdae293f75cdf729c6c00124e8489af2276 ] SCTP charges wmem_alloc via sctp_set_owner_w() in sctp_sendmsg() and via skb_set_owner_w() in sctp_packet_transmit(). If a sender runs out of sndbuf it will sleep in sctp_wait_for_sndbuf() and expects to be waken up by __sctp_write_space(). Buffer space charged via sctp_set_owner_w() is released in sctp_wfree() which calls __sctp_write_space() directly. Buffer space charged via skb_set_owner_w() is released via sock_wfree() which calls sk->sk_write_space() _if_ SOCK_USE_WRITE_QUEUE is not set. sctp_endpoint_init() sets SOCK_USE_WRITE_QUEUE on all sockets. Therefore if sctp_packet_transmit() manages to queue up more than sndbuf bytes, sctp_wait_for_sndbuf() will never be woken up again unless it is interrupted by a signal. This could be fixed by clearing the SOCK_USE_WRITE_QUEUE flag but ... Charging for the data twice does not make sense in the first place, it leads to overcharging sndbuf by a factor 2. Therefore this patch only charges a single byte in wmem_alloc when transmitting an SCTP packet to ensure that the socket stays alive until the packet has been released. This means that control chunks are no longer accounted for in wmem_alloc which I believe is not a problem as skb->truesize will typically lead to overcharging anyway and thus compensates for any control overhead. Signed-off-by: Thomas Graf <tgraf@suug.ch> CC: Vlad Yasevich <vyasevic@redhat.com> CC: Neil Horman <nhorman@tuxdriver.com> CC: David Miller <davem@davemloft.net> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Fix list corruption resulting from freeing an association on a listNeil Horman2012-08-192-7/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 2eebc1e188e9e45886ee00662519849339884d6d ] A few days ago Dave Jones reported this oops: [22766.294255] general protection fault: 0000 [#1] PREEMPT SMP [22766.295376] CPU 0 [22766.295384] Modules linked in: [22766.387137] ffffffffa169f292 6b6b6b6b6b6b6b6b ffff880147c03a90 ffff880147c03a74 [22766.387135] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 00000000000 [22766.387136] Process trinity-watchdo (pid: 10896, threadinfo ffff88013e7d2000, [22766.387137] Stack: [22766.387140] ffff880147c03a10 [22766.387140] ffffffffa169f2b6 [22766.387140] ffff88013ed95728 [22766.387143] 0000000000000002 [22766.387143] 0000000000000000 [22766.387143] ffff880003fad062 [22766.387144] ffff88013c120000 [22766.387144] [22766.387145] Call Trace: [22766.387145] <IRQ> [22766.387150] [<ffffffffa169f292>] ? __sctp_lookup_association+0x62/0xd0 [sctp] [22766.387154] [<ffffffffa169f2b6>] __sctp_lookup_association+0x86/0xd0 [sctp] [22766.387157] [<ffffffffa169f597>] sctp_rcv+0x207/0xbb0 [sctp] [22766.387161] [<ffffffff810d4da8>] ? trace_hardirqs_off_caller+0x28/0xd0 [22766.387163] [<ffffffff815827e3>] ? nf_hook_slow+0x133/0x210 [22766.387166] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387168] [<ffffffff8159043d>] ip_local_deliver_finish+0x18d/0x4c0 [22766.387169] [<ffffffff815902fc>] ? ip_local_deliver_finish+0x4c/0x4c0 [22766.387171] [<ffffffff81590a07>] ip_local_deliver+0x47/0x80 [22766.387172] [<ffffffff8158fd80>] ip_rcv_finish+0x150/0x680 [22766.387174] [<ffffffff81590c54>] ip_rcv+0x214/0x320 [22766.387176] [<ffffffff81558c07>] __netif_receive_skb+0x7b7/0x910 [22766.387178] [<ffffffff8155856c>] ? __netif_receive_skb+0x11c/0x910 [22766.387180] [<ffffffff810d423e>] ? put_lock_stats.isra.25+0xe/0x40 [22766.387182] [<ffffffff81558f83>] netif_receive_skb+0x23/0x1f0 [22766.387183] [<ffffffff815596a9>] ? dev_gro_receive+0x139/0x440 [22766.387185] [<ffffffff81559280>] napi_skb_finish+0x70/0xa0 [22766.387187] [<ffffffff81559cb5>] napi_gro_receive+0xf5/0x130 [22766.387218] [<ffffffffa01c4679>] e1000_receive_skb+0x59/0x70 [e1000e] [22766.387242] [<ffffffffa01c5aab>] e1000_clean_rx_irq+0x28b/0x460 [e1000e] [22766.387266] [<ffffffffa01c9c18>] e1000e_poll+0x78/0x430 [e1000e] [22766.387268] [<ffffffff81559fea>] net_rx_action+0x1aa/0x3d0 [22766.387270] [<ffffffff810a495f>] ? account_system_vtime+0x10f/0x130 [22766.387273] [<ffffffff810734d0>] __do_softirq+0xe0/0x420 [22766.387275] [<ffffffff8169826c>] call_softirq+0x1c/0x30 [22766.387278] [<ffffffff8101db15>] do_softirq+0xd5/0x110 [22766.387279] [<ffffffff81073bc5>] irq_exit+0xd5/0xe0 [22766.387281] [<ffffffff81698b03>] do_IRQ+0x63/0xd0 [22766.387283] [<ffffffff8168ee2f>] common_interrupt+0x6f/0x6f [22766.387283] <EOI> [22766.387284] [22766.387285] [<ffffffff8168eed9>] ? retint_swapgs+0x13/0x1b [22766.387285] Code: c0 90 5d c3 66 0f 1f 44 00 00 4c 89 c8 5d c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 5d e8 4c 89 65 f0 4c 89 6d f8 66 66 66 66 90 <0f> b7 87 98 00 00 00 48 89 fb 49 89 f5 66 c1 c0 08 66 39 46 02 [22766.387307] [22766.387307] RIP [22766.387311] [<ffffffffa168a2c9>] sctp_assoc_is_match+0x19/0x90 [sctp] [22766.387311] RSP <ffff880147c039b0> [22766.387142] ffffffffa16ab120 [22766.599537] ---[ end trace 3f6dae82e37b17f5 ]--- [22766.601221] Kernel panic - not syncing: Fatal exception in interrupt It appears from his analysis and some staring at the code that this is likely occuring because an association is getting freed while still on the sctp_assoc_hashtable. As a result, we get a gpf when traversing the hashtable while a freed node corrupts part of the list. Nominally I would think that an mibalanced refcount was responsible for this, but I can't seem to find any obvious imbalance. What I did note however was that the two places where we create an association using sctp_primitive_ASSOCIATE (__sctp_connect and sctp_sendmsg), have failure paths which free a newly created association after calling sctp_primitive_ASSOCIATE. sctp_primitive_ASSOCIATE brings us into the sctp_sf_do_prm_asoc path, which issues a SCTP_CMD_NEW_ASOC side effect, which in turn adds a new association to the aforementioned hash table. the sctp command interpreter that process side effects has not way to unwind previously processed commands, so freeing the association from the __sctp_connect or sctp_sendmsg error path would lead to a freed association remaining on this hash table. I've fixed this but modifying sctp_[un]hash_established to use hlist_del_init, which allows us to proerly use hlist_unhashed to check if the node is on a hashlist safely during a delete. That in turn alows us to safely call sctp_unhash_established in the __sctp_connect and sctp_sendmsg error paths before freeing them, regardles of what the associations state is on the hash list. I noted, while I was doing this, that the __sctp_unhash_endpoint was using hlist_unhsashed in a simmilar fashion, but never nullified any removed nodes pointers to make that function work properly, so I fixed that up in a simmilar fashion. I attempted to test this using a virtual guest running the SCTP_RR test from netperf in a loop while running the trinity fuzzer, both in a loop. I wasn't able to recreate the problem prior to this fix, nor was I able to trigger the failure after (neither of which I suppose is suprising). Given the trace above however, I think its likely that this is what we hit. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: davej@redhat.com CC: davej@redhat.com CC: "David S. Miller" <davem@davemloft.net> CC: Vlad Yasevich <vyasevich@gmail.com> CC: Sridhar Samudrala <sri@us.ibm.com> CC: linux-sctp@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: check cached dst before using itNicolas Dichtel2012-06-102-20/+1
| | | | | | | | | | | | [ Upstream commit e0268868ba064980488fc8c194db3d8e9fb2959c ] dst_check() will take care of SA (and obsolete field), hence IPsec rekeying scenario is taken into account. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Vlad Yaseivch <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Allow struct sctp_event_subscribe to grow without breaking binariesThomas Graf2012-05-111-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit acdd5985364f8dc511a0762fab2e683f29d9d692 ] getsockopt(..., SCTP_EVENTS, ...) performs a length check and returns an error if the user provides less bytes than the size of struct sctp_event_subscribe. Struct sctp_event_subscribe needs to be extended by an u8 for every new event or notification type that is added. This obviously makes getsockopt fail for binaries that are compiled against an older versions of <net/sctp/user.h> which do not contain all event types. This patch changes getsockopt behaviour to no longer return an error if not enough bytes are being provided by the user. Instead, it returns as much of sctp_event_subscribe as fits into the provided buffer. This leads to the new behavior that users see what they have been aware of at compile time. The setsockopt(..., SCTP_EVENTS, ...) API is already behaving like this. Signed-off-by: Thomas Graf <tgraf@suug.ch> Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
* sctp: Do not account for sizeof(struct sk_buff) in estimated rwndThomas Graf2011-12-202-11/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When checking whether a DATA chunk fits into the estimated rwnd a full sizeof(struct sk_buff) is added to the needed chunk size. This quickly exhausts the available rwnd space and leads to packets being sent which are much below the PMTU limit. This can lead to much worse performance. The reason for this behaviour was to avoid putting too much memory pressure on the receiver. The concept is not completely irational because a Linux receiver does in fact clone an skb for each DATA chunk delivered. However, Linux also reserves half the available socket buffer space for data structures therefore usage of it is already accounted for. When proposing to change this the last time it was noted that this behaviour was introduced to solve a performance issue caused by rwnd overusage in combination with small DATA chunks. Trying to reproduce this I found that with the sk_buff overhead removed, the performance would improve significantly unless socket buffer limits are increased. The following numbers have been gathered using a patched iperf supporting SCTP over a live 1 Gbit ethernet network. The -l option was used to limit DATA chunk sizes. The numbers listed are based on the average of 3 test runs each. Default values have been used for sk_(r|w)mem. Chunk Size Unpatched No Overhead ------------------------------------- 4 15.2 Kbit [!] 12.2 Mbit [!] 8 35.8 Kbit [!] 26.0 Mbit [!] 16 95.5 Kbit [!] 54.4 Mbit [!] 32 106.7 Mbit 102.3 Mbit 64 189.2 Mbit 188.3 Mbit 128 331.2 Mbit 334.8 Mbit 256 537.7 Mbit 536.0 Mbit 512 766.9 Mbit 766.6 Mbit 1024 810.1 Mbit 808.6 Mbit Signed-off-by: Thomas Graf <tgraf@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sctp: fix incorrect overflow check on autocloseXi Wang2011-12-194-3/+17
| | | | | | | | | | | | | | | | | | | | | | Commit 8ffd3208 voids the previous patches f6778aab and 810c0719 for limiting the autoclose value. If userspace passes in -1 on 32-bit platform, the overflow check didn't work and autoclose would be set to 0xffffffff. This patch defines a max_autoclose (in seconds) for limiting the value and exposes it through sysctl, with the following intentions. 1) Avoid overflowing autoclose * HZ. 2) Keep the default autoclose bound consistent across 32- and 64-bit platforms (INT_MAX / HZ in this patch). 3) Keep the autoclose value consistent between setsockopt() and getsockopt() calls. Suggested-by: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* sctp: better integer overflow check in sctp_auth_create_key()Xi Wang2011-11-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | The check from commit 30c2235c is incomplete and cannot prevent cases like key_len = 0x80000000 (INT_MAX + 1). In that case, the left-hand side of the check (INT_MAX - key_len), which is unsigned, becomes 0xffffffff (UINT_MAX) and bypasses the check. However this shouldn't be a security issue. The function is called from the following two code paths: 1) setsockopt() 2) sctp_auth_asoc_set_secret() In case (1), sca_keylength is never going to exceed 65535 since it's bounded by a u16 from the user API. As such, the key length will never overflow. In case (2), sca_keylength is computed based on the user key (1 short) and 2 * key_vector (3 shorts) for a total of 7 * USHRT_MAX, which still will not overflow. In other words, this overflow check is not really necessary. Just make it more correct. Signed-off-by: Xi Wang <xi.wang@gmail.com> Cc: Vlad Yasevich <vladislav.yasevich@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds2011-11-062-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
| * net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modulesPaul Gortmaker2011-10-312-0/+2
| | | | | | | | | | | | | | | | | | These files are non modular, but need to export symbols using the macros now living in export.h -- call out the include so that things won't break when we remove the implicit presence of module.h from everywhere. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAITEric Dumazet2011-10-271-1/+1
|/ | | | | | | | | | | | | | | commit 66b13d99d96a (ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT) fixed IPv4 only. This part is for the IPv6 side, adding a tclass param to ip6_xmit() We alias tw_tclass and tw_tos, if socket family is INET6. [ if sockets is ipv4-mapped, only IP_TOS socket option is used to fill TOS field, TCLASS is not taken into account ] Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: more accurate skb truesizeEric Dumazet2011-10-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | skb truesize currently accounts for sk_buff struct and part of skb head. kmalloc() roundings are also ignored. Considering that skb_shared_info is larger than sk_buff, its time to take it into account for better memory accounting. This patch introduces SKB_TRUESIZE(X) macro to centralize various assumptions into a single place. At skb alloc phase, we put skb_shared_info struct at the exact end of skb head, to allow a better use of memory (lowering number of reallocations), since kmalloc() gives us power-of-two memory blocks. Unless SLUB/SLUB debug is active, both skb->head and skb_shared_info are aligned to cache lines, as before. Note: This patch might trigger performance regressions because of misconfigured protocol stacks, hitting per socket or global memory limits that were previously not reached. But its a necessary step for a more accurate memory accounting. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Andi Kleen <ak@linux.intel.com> CC: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'master' of github.com:davem330/netDavid S. Miller2011-09-222-0/+11
|\ | | | | | | | | | | | | | | | | | | | | | | Conflicts: MAINTAINERS drivers/net/Kconfig drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c drivers/net/ethernet/broadcom/tg3.c drivers/net/wireless/iwlwifi/iwl-pci.c drivers/net/wireless/iwlwifi/iwl-trans-tx-pcie.c drivers/net/wireless/rt2x00/rt2800usb.c drivers/net/wireless/wl12xx/main.c
| * sctp: deal with multiple COOKIE_ECHO chunksMax Matveev2011-09-162-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Attempt to reduce the number of IP packets emitted in response to single SCTP packet (2e3216cd) introduced a complication - if a packet contains two COOKIE_ECHO chunks and nothing else then SCTP state machine corks the socket while processing first COOKIE_ECHO and then loses the association and forgets to uncork the socket. To deal with the issue add new SCTP command which can be used to set association explictly. Use this new command when processing second COOKIE_ECHO chunk to restore the context for SCTP state machine. Signed-off-by: Max Matveev <makc@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | sctp: Bundle HEAERTBEAT into ASCONF_ACKMichio Honda2011-08-243-0/+7
| | | | | | | | | | | | | | | | | | With this patch a HEARTBEAT chunk is bundled into the ASCONF-ACK for ADD IP ADDRESS, confirming the new destination as quickly as possible. Signed-off-by: Michio Honda <micchie@sfc.wide.ad.jp> Signed-off-by: David S. Miller <davem@davemloft.net>