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: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/netdev/Z2K%2FI4nlHdfMRTZC@v4bel-B760M-AORUS-ELITE-AX/
Link: https://lore.kernel.org/netdev/5ca20d4c-1017-49c2-9516-f6f75fd331e9@xxxxxxx/
Link: https://lore.kernel.org/netdev/677f84a8.050a0220.25a300.01b3.GAE@xxxxxxxxxx/
Co-developed-by: Hyunwoo Kim <v4bel@xxxxxxxxx>
Signed-off-by: Hyunwoo Kim <v4bel@xxxxxxxxx>
Co-developed-by: Wongi Lee <qwerty@xxxxxxxxx>
Signed-off-by: Wongi Lee <qwerty@xxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
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
