From 98eee187cdee2807bd80e6c02180c5c2abae6453 Mon Sep 17 00:00:00 2001 From: "bingtian.ly@taobao.com" Date: Wed, 23 Jan 2013 20:35:28 +0000 Subject: net: avoid to hang up on sending due to sysctl configuration overflow. commit cdda88912d62f9603d27433338a18be83ef23ac1 upstream. I found if we write a larger than 4GB value to some sysctl variables, the sending syscall will hang up forever, because these variables are 32 bits, such large values make them overflow to 0 or negative. This patch try to fix overflow or prevent from zero value setup of below sysctl variables: net.core.wmem_default net.core.rmem_default net.core.rmem_max net.core.wmem_max net.ipv4.udp_rmem_min net.ipv4.udp_wmem_min net.ipv4.tcp_wmem net.ipv4.tcp_rmem Signed-off-by: Eric Dumazet Signed-off-by: Li Yu Signed-off-by: David S. Miller [bwh: Backported to 3.2: - Adjust context - Delete now-unused 'zero' variable] Signed-off-by: Ben Hutchings --- net/core/sysctl_net_core.c | 14 ++++++++++---- net/ipv4/sysctl_net_ipv4.c | 12 +++++++----- 2 files changed, 17 insertions(+), 9 deletions(-) (limited to 'net') diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index f0bdd36..69320bd 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -22,6 +22,8 @@ static int zero = 0; static int ushort_max = USHRT_MAX; +static int one = 1; + #ifdef CONFIG_RPS static int rps_sock_flow_sysctl(ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) @@ -89,28 +91,32 @@ static struct ctl_table net_core_table[] = { .data = &sysctl_wmem_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, }, { .procname = "rmem_max", .data = &sysctl_rmem_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, }, { .procname = "wmem_default", .data = &sysctl_wmem_default, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, }, { .procname = "rmem_default", .data = &sysctl_rmem_default, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, }, { .procname = "dev_weight", diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 739b073..253dd80 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -24,7 +24,7 @@ #include #include -static int zero; +static int one = 1; static int tcp_retr1_max = 255; static int ip_local_port_range_min[] = { 1, 1 }; static int ip_local_port_range_max[] = { 65535, 65535 }; @@ -448,14 +448,16 @@ static struct ctl_table ipv4_table[] = { .data = &sysctl_tcp_wmem, .maxlen = sizeof(sysctl_tcp_wmem), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, }, { .procname = "tcp_rmem", .data = &sysctl_tcp_rmem, .maxlen = sizeof(sysctl_tcp_rmem), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, }, { .procname = "tcp_app_win", @@ -662,7 +664,7 @@ static struct ctl_table ipv4_table[] = { .maxlen = sizeof(sysctl_udp_rmem_min), .mode = 0644, .proc_handler = proc_dointvec_minmax, - .extra1 = &zero + .extra1 = &one }, { .procname = "udp_wmem_min", @@ -670,7 +672,7 @@ static struct ctl_table ipv4_table[] = { .maxlen = sizeof(sysctl_udp_wmem_min), .mode = 0644, .proc_handler = proc_dointvec_minmax, - .extra1 = &zero + .extra1 = &one }, { } }; -- cgit v1.1