5.10-stable review patch. If anyone has any objections, please let me know.
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From: Stefano Garzarella sgarzare@redhat.com
commit 2cb7c756f605ec02ffe562fb26828e4bcc5fdfc1 upstream.
If the socket has been de-assigned or assigned to another transport, we must discard any packets received because they are not expected and would cause issues when we access vsk->transport.
A possible scenario is described by Hyunwoo Kim in the attached link, where after a first connect() interrupted by a signal, and a second connect() failed, we can find `vsk->transport` at NULL, leading to a NULL pointer dereference.
Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Cc: stable@vger.kernel.org Reported-by: Hyunwoo Kim v4bel@theori.io Reported-by: Wongi Lee qwerty@theori.io Closes: https://lore.kernel.org/netdev/Z2LvdTTQR7dBmPb5@v4bel-B760M-AORUS-ELITE-AX/ Signed-off-by: Stefano Garzarella sgarzare@redhat.com Reviewed-by: Hyunwoo Kim v4bel@theori.io Signed-off-by: Paolo Abeni pabeni@redhat.com [SG: fixed context conflict since this tree is missing commit 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")] Signed-off-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/vmw_vsock/virtio_transport_common.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1171,8 +1171,11 @@ void virtio_transport_recv_pkt(struct vi
lock_sock(sk);
- /* Check if sk has been closed before lock_sock */ - if (sock_flag(sk, SOCK_DONE)) { + /* Check if sk has been closed or assigned to another transport before + * lock_sock (note: listener sockets are not assigned to any transport) + */ + if (sock_flag(sk, SOCK_DONE) || + (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) { (void)virtio_transport_reset_no_sock(t, pkt); release_sock(sk); sock_put(sk);