From 6151b31c9616d71f714fc7ef8e2306f67f3b94c3 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Fri, 4 Nov 2005 09:56:56 +1100 Subject: [PATCH] [NET]: Fix race condition in sk_stream_wait_connect When sk_stream_wait_connect detects a state transition to ESTABLISHED or CLOSE_WAIT prior to it going to sleep, it will return without calling finish_wait and decrementing sk_write_pending. This may result in crashes and other unintended behaviour. The fix is to always call finish_wait and update sk_write_pending since it is safe to do so even if the wait entry is no longer on the queue. This bug was tracked down with the help of Alex Sidorenko and the fix is also based on his suggestion. Signed-off-by: Herbert Xu Signed-off-by: Arnaldo Carvalho de Melo --- net/core/stream.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/net/core/stream.c b/net/core/stream.c index ac9edfdf8742..15bfd03e8024 100644 --- a/net/core/stream.c +++ b/net/core/stream.c @@ -52,8 +52,9 @@ int sk_stream_wait_connect(struct sock *sk, long *timeo_p) { struct task_struct *tsk = current; DEFINE_WAIT(wait); + int done; - while (1) { + do { if (sk->sk_err) return sock_error(sk); if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) @@ -65,13 +66,12 @@ int sk_stream_wait_connect(struct sock *sk, long *timeo_p) prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); sk->sk_write_pending++; - if (sk_wait_event(sk, timeo_p, - !((1 << sk->sk_state) & - ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))) - break; + done = sk_wait_event(sk, timeo_p, + !((1 << sk->sk_state) & + ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))); finish_wait(sk->sk_sleep, &wait); sk->sk_write_pending--; - } + } while (!done); return 0; } -- GitLab