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| author | Paolo Abeni <pabeni@redhat.com> | 2023-10-11 09:20:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-25 12:16:21 +0200 |
| commit | 30fa7600e0580cabbbc50e1c94b5609a85469809 (patch) | |
| tree | 9da9724efebab17b2e9e250c3ac59aa2b3a08fb4 /net/mptcp | |
| parent | 3d45ae77292e5697366362b2393565eaed6789bd (diff) | |
| download | linux-stable-30fa7600e0580cabbbc50e1c94b5609a85469809.tar.gz linux-stable-30fa7600e0580cabbbc50e1c94b5609a85469809.tar.bz2 linux-stable-30fa7600e0580cabbbc50e1c94b5609a85469809.zip | |
tcp: allow again tcp_disconnect() when threads are waiting
[ Upstream commit 419ce133ab928ab5efd7b50b2ef36ddfd4eadbd2 ]
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 <tdeseyn@redhat.com>
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1886305
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/f3b95e47e3dbed840960548aebaa8d954372db41.1697008693.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/protocol.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index d2a47c6f9655..0850d6a43049 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3063,12 +3063,6 @@ static int mptcp_disconnect(struct sock *sk, int flags) { struct mptcp_sock *msk = mptcp_sk(sk); - /* Deny disconnect if other threads are blocked in sk_wait_event() - * or inet_wait_for_connect(). - */ - if (sk->sk_wait_pending) - return -EBUSY; - /* We are on the fastopen error path. We can't call straight into the * subflows cleanup code due to lock nesting (we are already under * msk->firstsocket lock). @@ -3139,7 +3133,6 @@ struct sock *mptcp_sk_clone_init(const struct sock *sk, inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk); #endif - nsk->sk_wait_pending = 0; __mptcp_init_sock(nsk); msk = mptcp_sk(nsk); |