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| author | subashab@codeaurora.org <subashab@codeaurora.org> | 2015-01-23 22:26:02 +0000 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-05-09 23:16:37 +0100 |
| commit | cfd16467dd2b98642b547df2d25121b7c1599462 (patch) | |
| tree | caf3564d70d83734148b6b3308dcc240774c81e8 /net/ipv4 | |
| parent | c9568b84ff6fd86075ec67cb9368e8fde1f249ce (diff) | |
| download | kernel_samsung_smdk4412-cfd16467dd2b98642b547df2d25121b7c1599462.zip kernel_samsung_smdk4412-cfd16467dd2b98642b547df2d25121b7c1599462.tar.gz kernel_samsung_smdk4412-cfd16467dd2b98642b547df2d25121b7c1599462.tar.bz2 | |
ping: Fix race in free in receive path
[ Upstream commit fc752f1f43c1c038a2c6ae58cc739ebb5953ccb0 ]
An exception is seen in ICMP ping receive path where the skb
destructor sock_rfree() tries to access a freed socket. This happens
because ping_rcv() releases socket reference with sock_put() and this
internally frees up the socket. Later icmp_rcv() will try to free the
skb and as part of this, skb destructor is called and which leads
to a kernel panic as the socket is freed already in ping_rcv().
-->|exception
-007|sk_mem_uncharge
-007|sock_rfree
-008|skb_release_head_state
-009|skb_release_all
-009|__kfree_skb
-010|kfree_skb
-011|icmp_rcv
-012|ip_local_deliver_finish
Fix this incorrect free by cloning this skb and processing this cloned
skb instead.
This patch was suggested by Eric Dumazet
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ping.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 6d62262..0e91ae3 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -717,8 +717,11 @@ void ping_rcv(struct sk_buff *skb) sk = ping_v4_lookup(net, saddr, daddr, ntohs(icmph->un.echo.id), skb->dev->ifindex); if (sk != NULL) { + struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); + pr_debug("rcv on socket %p\n", sk); - ping_queue_rcv_skb(sk, skb_get(skb)); + if (skb2) + ping_queue_rcv_skb(sk, skb2); sock_put(sk); return; } |