[PATCH net 5/5] afs: Fix uncancelled rxrpc OOB message handler

[David Howells <dhowells@redhat.com>]

Fix AFS to cancel its OOB message processing (typically to respond to
security challenges).  Also move OOB message processing to afs_wq so that
it's also waited for and make the OOB handler just return if the net
namespace is no longer live.

Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE")
Link: https://sashiko.dev/#/patchset/20260609140911.838677-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Li Daming <d4n.for.sec@gmail.com>
cc: Ren Wei <n05ec@lzu.edu.cn>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeffrey Altman <jaltman@auristor.com>
cc: Eric Dumazet <edumazet@google.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
---
 fs/afs/cm_security.c | 3 ++-
 fs/afs/rxrpc.c       | 4 +++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/afs/cm_security.c b/fs/afs/cm_security.c
index edcbd249d202..103168c70dd4 100644
--- a/fs/afs/cm_security.c
+++ b/fs/afs/cm_security.c
@@ -101,7 +101,8 @@ void afs_process_oob_queue(struct work_struct *work)
 	struct sk_buff *oob;
 	enum rxrpc_oob_type type;
 
-	while ((oob = rxrpc_kernel_dequeue_oob(net->socket, &type))) {
+	while (READ_ONCE(net->live) &&
+	       (oob = rxrpc_kernel_dequeue_oob(net->socket, &type))) {
 		switch (type) {
 		case RXRPC_OOB_CHALLENGE:
 			afs_respond_to_challenge(oob);
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index fd2d260fb25f..6241f9349f6b 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -128,6 +128,7 @@ void afs_close_socket(struct afs_net *net)
 	_enter("");
 
 	cancel_work_sync(&net->charge_preallocation_work);
+	cancel_work_sync(&net->rx_oob_work);
 	kernel_listen(net->socket, 0);
 	flush_workqueue(afs_async_calls);
 	flush_workqueue(afs_wq);
@@ -985,5 +986,6 @@ static void afs_rx_notify_oob(struct sock *sk, struct sk_buff *oob)
 {
 	struct afs_net *net = sk->sk_user_data;
 
-	schedule_work(&net->rx_oob_work);
+	if (net->live)
+		queue_work(afs_wq, &net->rx_oob_work);
 }