FAILED: patch "[PATCH] rxrpc: Fix socket notification race" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x e66f8f32f50116670dbbee5bc9e692cd2cd0c8f8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026072024-trench-preplan-05a9@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e66f8f32f50116670dbbee5bc9e692cd2cd0c8f8 Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Wed, 24 Jun 2026 17:38:16 +0100
Subject: [PATCH] rxrpc: Fix socket notification race

There's a race between rxrpc_recvmsg() and rxrpc_notify_socket(), whereby
the latter's attempt to avoid disabling interrupts and taking the socket's
recvmsg_lock if the call is already queued may happen simultaneously with
the former's discarding of a call that has nothing queued.

Fix this by removing the shortcut.  Note that this only affects userspace's
use of AF_RXRPC; the AFS filesystem driver doesn't use the socket queue.

Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code")
Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeffrey Altman <jaltman@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260624163819.3017002-10-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index f382a47c6eb0..9962e135cb73 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -27,8 +27,6 @@ void rxrpc_notify_socket(struct rxrpc_call *call)
 
 	_enter("%d", call->debug_id);
 
-	if (!list_empty(&call->recvmsg_link))
-		return;
 	if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
 		rxrpc_see_call(call, rxrpc_call_see_notify_released);
 		return;