From 419ce133ab928ab5efd7b50b2ef36ddfd4eadbd2 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Wed, 11 Oct 2023 09:20:55 +0200 Subject: tcp: allow again tcp_disconnect() when threads are waiting As reported by Tom, .NET and applications build on top of it rely on connect(AF_UNSPEC) to async cancel pending I/O operations on TCP socket. The blamed commit below caused a regression, as such cancellation can now fail. As suggested by Eric, this change addresses the problem explicitly causing blocking I/O operation to terminate immediately (with an error) when a concurrent disconnect() is executed. Instead of tracking the number of threads blocked on a given socket, track the number of disconnect() issued on such socket. If such counter changes after a blocking operation releasing and re-acquiring the socket lock, error out the current operation. Fixes: 4faeee0cf8a5 ("tcp: deny tcp_disconnect() when threads are waiting") Reported-by: Tom Deseyn Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305 Suggested-by: Eric Dumazet Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski --- net/tls/tls_main.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'net/tls/tls_main.c') diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 02f583ff9239..002483e60c19 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -139,8 +139,8 @@ void update_sk_prot(struct sock *sk, struct tls_context *ctx) int wait_on_pending_writer(struct sock *sk, long *timeo) { - int rc = 0; DEFINE_WAIT_FUNC(wait, woken_wake_function); + int ret, rc = 0; add_wait_queue(sk_sleep(sk), &wait); while (1) { @@ -154,9 +154,13 @@ int wait_on_pending_writer(struct sock *sk, long *timeo) break; } - if (sk_wait_event(sk, timeo, - !READ_ONCE(sk->sk_write_pending), &wait)) + ret = sk_wait_event(sk, timeo, + !READ_ONCE(sk->sk_write_pending), &wait); + if (ret) { + if (ret < 0) + rc = ret; break; + } } remove_wait_queue(sk_sleep(sk), &wait); return rc; -- cgit v1.2.3