diff options
| author | Longpeng(Mike) <longpeng2@huawei.com> | 2021-08-12 13:30:56 +0800 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2021-08-26 08:37:02 -0400 |
| commit | 8dc6941d5b991d605999c8ec01d46d51d6afc55e (patch) | |
| tree | 000dac022831191dcdeb75da52e0540f82b12c4f /net | |
| parent | 47501793183e28578338ee4f32936d99e28a6bc1 (diff) | |
vsock/virtio: avoid potential deadlock when vsock device remove
[ Upstream commit 49b0b6ffe20c5344f4173f3436298782a08da4f2 ]
There's a potential deadlock case when remove the vsock device or
process the RESET event:
vsock_for_each_connected_socket:
spin_lock_bh(&vsock_table_lock) ----------- (1)
...
virtio_vsock_reset_sock:
lock_sock(sk) --------------------- (2)
...
spin_unlock_bh(&vsock_table_lock)
lock_sock() may do initiative schedule when the 'sk' is owned by
other thread at the same time, we would receivce a warning message
that "scheduling while atomic".
Even worse, if the next task (selected by the scheduler) try to
release a 'sk', it need to request vsock_table_lock and the deadlock
occur, cause the system into softlockup state.
Call trace:
queued_spin_lock_slowpath
vsock_remove_bound
vsock_remove_sock
virtio_transport_release
__vsock_release
vsock_release
__sock_release
sock_close
__fput
____fput
So we should not require sk_lock in this case, just like the behavior
in vhost_vsock or vmci.
Fixes: 0ea9e1d3a9e3 ("VSOCK: Introduce virtio_transport.ko")
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20210812053056.1699-1-longpeng2@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/vmw_vsock/virtio_transport.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index cc70d651d13e..e34979fcefd2 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -373,11 +373,14 @@ static void virtio_vsock_event_fill(struct virtio_vsock *vsock) static void virtio_vsock_reset_sock(struct sock *sk) { - lock_sock(sk); + /* vmci_transport.c doesn't take sk_lock here either. At least we're + * under vsock_table_lock so the sock cannot disappear while we're + * executing. + */ + sk->sk_state = TCP_CLOSE; sk->sk_err = ECONNRESET; sk->sk_error_report(sk); - release_sock(sk); } static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock) |