diff options
| author | Daniel Borkmann <daniel@iogearbox.net> | 2018-10-16 21:31:35 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-10-16 12:38:41 -0700 |
| commit | aadd4355918fe6e9044a9042fa5968e0a0901681 (patch) | |
| tree | bde5becd6794d32ac8fb2c951570b705266cc162 | |
| parent | 29ce85f349c2f77a3c035f70fafeaa8b22608328 (diff) | |
tcp, ulp: remove socket lock assertion on ULP cleanup
Eric reported that syzkaller triggered a splat in tcp_cleanup_ulp()
where assertion sock_owned_by_me() failed. This happened through
inet_csk_prepare_forced_close() first releasing the socket lock,
then calling into tcp_done(newsk) which is called after the
inet_csk_prepare_forced_close() and therefore without the socket
lock held. The sock_owned_by_me() assertion can generally be
removed as the only place where tcp_cleanup_ulp() is called from
now is out of inet_csk_destroy_sock() -> sk->sk_prot->destroy()
where socket is in dead state and unreachable. Therefore, add a
comment why the check is not needed instead.
Fixes: 8b9088f806e1 ("tcp, ulp: enforce sock_owned_by_me upon ulp init and cleanup")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/tcp_ulp.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c index a9162aa11af9..95df7f7f6328 100644 --- a/net/ipv4/tcp_ulp.c +++ b/net/ipv4/tcp_ulp.c @@ -99,8 +99,10 @@ void tcp_cleanup_ulp(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); - sock_owned_by_me(sk); - + /* No sock_owned_by_me() check here as at the time the + * stack calls this function, the socket is dead and + * about to be destroyed. + */ if (!icsk->icsk_ulp_ops) return; |