diff options
| author | Scott Mayhew <smayhew@redhat.com> | 2025-12-09 14:30:15 -0500 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-12-18 16:01:36 +0100 |
| commit | 15564bd67e2975002f2a8e9defee33e321d3183f (patch) | |
| tree | 8add06ba3768f04350d7a99284efc03b7814a351 | |
| parent | 3e82accd3e9c35acfc68e44e12b37e5fd350c768 (diff) | |
net/handshake: duplicate handshake cancellations leak socket
When a handshake request is cancelled it is removed from the
handshake_net->hn_requests list, but it is still present in the
handshake_rhashtbl until it is destroyed.
If a second cancellation request arrives for the same handshake request,
then remove_pending() will return false... and assuming
HANDSHAKE_F_REQ_COMPLETED isn't set in req->hr_flags, we'll continue
processing through the out_true label, where we put another reference on
the sock and a refcount underflow occurs.
This can happen for example if a handshake times out - particularly if
the SUNRPC client sends the AUTH_TLS probe to the server but doesn't
follow it up with the ClientHello due to a problem with tlshd. When the
timeout is hit on the server, the server will send a FIN, which triggers
a cancellation request via xs_reset_transport(). When the timeout is
hit on the client, another cancellation request happens via
xs_tls_handshake_sync().
Add a test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED) in the pending cancel
path so duplicate cancels can be detected.
Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests")
Suggested-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://patch.msgid.link/20251209193015.3032058-1-smayhew@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/handshake/request.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/handshake/request.c b/net/handshake/request.c index 89435ed755cd..6b7e3e0bf399 100644 --- a/net/handshake/request.c +++ b/net/handshake/request.c @@ -326,7 +326,11 @@ bool handshake_req_cancel(struct sock *sk) hn = handshake_pernet(net); if (hn && remove_pending(hn, req)) { - /* Request hadn't been accepted */ + /* Request hadn't been accepted - mark cancelled */ + if (test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED, &req->hr_flags)) { + trace_handshake_cancel_busy(net, req, sk); + return false; + } goto out_true; } if (test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED, &req->hr_flags)) { |