From 2903037400a26e7c0cc93ab75a7d62abfacdf485 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 29 May 2010 00:20:48 -0700 Subject: [PATCH] net: fix sk_forward_alloc corruptions As David found out, sock_queue_err_skb() should be called with socket lock hold, or we risk sk_forward_alloc corruption, since we use non atomic operations to update this field. This patch adds bh_lock_sock()/bh_unlock_sock() pair to three spots. (BH already disabled) 1) skb_tstamp_tx() 2) Before calling ip_icmp_error(), in __udp4_lib_err() 3) Before calling ipv6_icmp_error(), in __udp6_lib_err() Reported-by: Anton Blanchard Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/skbuff.c | 4 ++++ net/ipv4/udp.c | 2 ++ net/ipv6/udp.c | 6 ++++-- 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 4667d4d..f2913ae 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2992,7 +2992,11 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, memset(serr, 0, sizeof(*serr)); serr->ee.ee_errno = ENOMSG; serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; + + bh_lock_sock(sk); err = sock_queue_err_skb(sk, skb); + bh_unlock_sock(sk); + if (err) kfree_skb(skb); } diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index b9d0d40..acdc9be 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -634,7 +634,9 @@ void __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) if (!harderr || sk->sk_state != TCP_ESTABLISHED) goto out; } else { + bh_lock_sock(sk); ip_icmp_error(sk, skb, err, uh->dest, info, (u8 *)(uh+1)); + bh_unlock_sock(sk); } sk->sk_err = err; sk->sk_error_report(sk); diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 87be586..3048f90 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -466,9 +466,11 @@ void __udp6_lib_err(struct sk_buff *skb, struct inet6_skb_parm *opt, if (sk->sk_state != TCP_ESTABLISHED && !np->recverr) goto out; - if (np->recverr) + if (np->recverr) { + bh_lock_sock(sk); ipv6_icmp_error(sk, skb, err, uh->dest, ntohl(info), (u8 *)(uh+1)); - + bh_unlock_sock(sk); + } sk->sk_err = err; sk->sk_error_report(sk); out: -- 2.7.4