FAILED: patch "[PATCH] Input: byd - synchronize timer deletion before freeing" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] Input: byd - synchronize timer deletion before freeing" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x c83e79c0842ed29860648bcce5022ef0ba5001c6
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026082045-whoopee-batboy-8ace@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From c83e79c0842ed29860648bcce5022ef0ba5001c6 Mon Sep 17 00:00:00 2001
From: Linmao Li <lilinmao@kylinos.cn>
Date: Mon, 20 Jul 2026 14:12:59 +0800
Subject: [PATCH] Input: byd - synchronize timer deletion before freeing
 private data

byd_disconnect() uses timer_delete() before freeing the driver's private
data.  This does not wait for a running byd_clear_touch() callback, which
dereferences the private data and its psmouse pointer.  A callback racing
with disconnect can therefore access the private data after it has been
freed.  The timer can also still be re-armed by byd_process_byte() while
the disconnect is in progress.

Use timer_shutdown_sync() before freeing the private data: it waits for
a running callback and turns any later re-arm attempt into a no-op.

Fixes: 2d5f5611dd0d ("Input: byd - enable absolute mode")
Cc: stable@vger.kernel.org
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Link: https://patch.msgid.link/20260720061259.1601281-1-lilinmao@kylinos.cn
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index f5770a3af2f1..5fc3c629590a 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -423,7 +423,7 @@ static void byd_disconnect(struct psmouse *psmouse)
 	struct byd_data *priv = psmouse->private;
 
 	if (priv) {
-		timer_delete(&priv->timer);
+		timer_shutdown_sync(&priv->timer);
 		kfree(psmouse->private);
 		psmouse->private = NULL;
 	}

[PATCH 6.1.y] Input: byd - synchronize timer deletion before freeing private data

[Sasha Levin]

From: Linmao Li <lilinmao@kylinos.cn>

[ Upstream commit c83e79c0842ed29860648bcce5022ef0ba5001c6 ]

byd_disconnect() uses timer_delete() before freeing the driver's private
data.  This does not wait for a running byd_clear_touch() callback, which
dereferences the private data and its psmouse pointer.  A callback racing
with disconnect can therefore access the private data after it has been
freed.  The timer can also still be re-armed by byd_process_byte() while
the disconnect is in progress.

Use timer_shutdown_sync() before freeing the private data: it waits for
a running callback and turns any later re-arm attempt into a no-op.

Fixes: 2d5f5611dd0d ("Input: byd - enable absolute mode")
Cc: stable@vger.kernel.org
Signed-off-by: Linmao Li <lilinmao@kylinos.cn>
Link: https://patch.msgid.link/20260720061259.1601281-1-lilinmao@kylinos.cn
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
[ changed `del_timer()` to `timer_shutdown_sync()` since 6.12 predates the `del_timer()` → `timer_delete()` rename ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/input/mouse/byd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/input/mouse/byd.c b/drivers/input/mouse/byd.c
index 221a553f45cd8..cb49f38883020 100644
--- a/drivers/input/mouse/byd.c
+++ b/drivers/input/mouse/byd.c
@@ -426,7 +426,7 @@ static void byd_disconnect(struct psmouse *psmouse)
 	struct byd_data *priv = psmouse->private;
 
 	if (priv) {
-		del_timer(&priv->timer);
+		timer_shutdown_sync(&priv->timer);
 		kfree(psmouse->private);
 		psmouse->private = NULL;
 	}
-- 
2.53.0