FAILED: patch "[PATCH] Bluetooth: L2CAP: Fix null-ptr-deref in" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 78a88d43dab8d23aeef934ed8ce34d40e6b3d613
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051217-erasure-slick-6fb7@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 78a88d43dab8d23aeef934ed8ce34d40e6b3d613 Mon Sep 17 00:00:00 2001
From: Siwei Zhang <oss@fourdim.xyz>
Date: Wed, 15 Apr 2026 16:53:36 -0400
Subject: [PATCH] Bluetooth: L2CAP: Fix null-ptr-deref in
 l2cap_sock_get_sndtimeo_cb()

Add the same NULL guard already present in
l2cap_sock_resume_cb() and l2cap_sock_ready_cb().

Fixes: 8d836d71e222 ("Bluetooth: Access sk_sndtimeo indirectly in l2cap_core.c")
Cc: stable@kernel.org
Signed-off-by: Siwei Zhang <oss@fourdim.xyz>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index fb3cb70a5a39..879c9f90269a 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1761,6 +1761,9 @@ static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
 {
 	struct sock *sk = chan->data;
 
+	if (!sk)
+		return 0;
+
 	return READ_ONCE(sk->sk_sndtimeo);
 }