On Fri, Jan 10, 2025 at 09:35:11AM +0100, Stefano Garzarella wrote:
Recent reports have shown how we sometimes call vsock_*_has_data() when a vsock socket has been de-assigned from a transport (see attached links), but we shouldn't.Previous commits should have solved the real problems, but we may have more in the future, so to avoid null-ptr-deref, we can return 0 (no space, no data available) but with a warning. This way the code should continue to run in a nearly consistent state and have a warning that allows us to debug future problems. Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Cc: [email protected] Link: https://lore.kernel.org/netdev/Z2K%2FI4nlHdfMRTZC@v4bel-B760M-AORUS-ELITE-AX/ Link: https://lore.kernel.org/netdev/[email protected]/ Link: https://lore.kernel.org/netdev/[email protected]/ Co-developed-by: Hyunwoo Kim <[email protected]> Signed-off-by: Hyunwoo Kim <[email protected]> Co-developed-by: Wongi Lee <[email protected]> Signed-off-by: Wongi Lee <[email protected]> Signed-off-by: Stefano Garzarella <[email protected]> --- net/vmw_vsock/af_vsock.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 74d35a871644..fa9d1b49599b 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -879,6 +879,9 @@ EXPORT_SYMBOL_GPL(vsock_create_connected); s64 vsock_stream_has_data(struct vsock_sock *vsk) { + if (WARN_ON(!vsk->transport)) + return 0; + return vsk->transport->stream_has_data(vsk); } EXPORT_SYMBOL_GPL(vsock_stream_has_data); @@ -887,6 +890,9 @@ s64 vsock_connectible_has_data(struct vsock_sock *vsk) { struct sock *sk = sk_vsock(vsk); + if (WARN_ON(!vsk->transport)) + return 0; + if (sk->sk_type == SOCK_SEQPACKET) return vsk->transport->seqpacket_has_data(vsk); else @@ -896,6 +902,9 @@ EXPORT_SYMBOL_GPL(vsock_connectible_has_data); s64 vsock_stream_has_space(struct vsock_sock *vsk) { + if (WARN_ON(!vsk->transport)) + return 0; + return vsk->transport->stream_has_space(vsk); } EXPORT_SYMBOL_GPL(vsock_stream_has_space); -- 2.47.1
Reviewed-by: Luigi Leonardi <[email protected]> Thanks! Luigi
