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| author | Tom Marshall <tdm.code@gmail.com> | 2010-09-20 15:42:05 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-09-20 15:42:05 -0700 |
| commit | a4d258036ed9b2a1811c3670c6099203a0f284a0 (patch) | |
| tree | 58412022664aef745a99d254d20cf1a66aabda44 /net/ipv4/tcp_input.c | |
| parent | 9828e6e6e3f19efcb476c567b9999891d051f52f (diff) | |
| download | op-kernel-dev-a4d258036ed9b2a1811c3670c6099203a0f284a0.zip op-kernel-dev-a4d258036ed9b2a1811c3670c6099203a0f284a0.tar.gz | |
tcp: Fix race in tcp_poll
If a RST comes in immediately after checking sk->sk_err, tcp_poll will
return POLLIN but not POLLOUT. Fix this by checking sk->sk_err at the end
of tcp_poll. Additionally, ensure the correct order of operations on SMP
machines with memory barriers.
Signed-off-by: Tom Marshall <tdm.code@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e663b78..149e79a 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4048,6 +4048,8 @@ static void tcp_reset(struct sock *sk) default: sk->sk_err = ECONNRESET; } + /* This barrier is coupled with smp_rmb() in tcp_poll() */ + smp_wmb(); if (!sock_flag(sk, SOCK_DEAD)) sk->sk_error_report(sk); |
