From: Norbert Slusarek <nslusarek@xxxxxxx> commit 3d0bc44d39bca615b72637e340317b7899b7f911 upstream. A possible locking issue in vsock_connect_timeout() was recognized by Eric Dumazet which might cause a null pointer dereference in vsock_transport_cancel_pkt(). This patch assures that vsock_transport_cancel_pkt() will be called within the lock, so a race condition won't occur which could result in vsk->transport to be set to NULL. Fixes: 380feae0def7 ("vsock: cancel packets when failing to connect") Reported-by: Eric Dumazet <eric.dumazet@xxxxxxxxx> Signed-off-by: Norbert Slusarek <nslusarek@xxxxxxx> Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> Link: https://lore.kernel.org/r/trinity-f8e0937a-cf0e-4d80-a76e-d9a958ba3ef1-1612535522360@3c-app-gmx-bap12 Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/vmw_vsock/af_vsock.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1121,7 +1121,6 @@ static void vsock_connect_timeout(struct { struct sock *sk; struct vsock_sock *vsk; - int cancel = 0; vsk = container_of(work, struct vsock_sock, connect_work.work); sk = sk_vsock(vsk); @@ -1132,11 +1131,9 @@ static void vsock_connect_timeout(struct sk->sk_state = SS_UNCONNECTED; sk->sk_err = ETIMEDOUT; sk->sk_error_report(sk); - cancel = 1; + vsock_transport_cancel_pkt(vsk); } release_sock(sk); - if (cancel) - vsock_transport_cancel_pkt(vsk); sock_put(sk); }