From 7224283df47b5ff9f309371b60030f07037cd51e Mon Sep 17 00:00:00 2001 From: Robert Varga Date: Tue, 15 Sep 2009 23:49:21 -0700 Subject: tcp: fix CONFIG_TCP_MD5SIG + CONFIG_PREEMPT timer BUG() commit 657e9649e745b06675aa5063c84430986cdc3afa upstream. I have recently came across a preemption imbalance detected by: <4>huh, entered ffffffff80644630 with preempt_count 00000102, exited with 00000101? <0>------------[ cut here ]------------ <2>kernel BUG at /usr/src/linux/kernel/timer.c:664! <0>invalid opcode: 0000 [1] PREEMPT SMP with ffffffff80644630 being inet_twdr_hangman(). This appeared after I enabled CONFIG_TCP_MD5SIG and played with it a bit, so I looked at what might have caused it. One thing that struck me as strange is tcp_twsk_destructor(), as it calls tcp_put_md5sig_pool() -- which entails a put_cpu(), causing the detected imbalance. Found on 2.6.23.9, but 2.6.31 is affected as well, as far as I can tell. Signed-off-by: Robert Varga Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_minisocks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index f976fc57892c..6d108fbcb7c2 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -362,7 +362,7 @@ void tcp_twsk_destructor(struct sock *sk) #ifdef CONFIG_TCP_MD5SIG struct tcp_timewait_sock *twsk = tcp_twsk(sk); if (twsk->tw_md5_keylen) - tcp_put_md5sig_pool(); + tcp_free_md5sig_pool(); #endif } -- cgit v1.2.3