[PATCH 5.10.y] Input: ims-pcu - fix race condition in reset_device sysfs callback

[Sasha Levin <sashal@kernel.org>]

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

[ Upstream commit 411b8c4b274737c3bf08e1e025801161603cfffc ]

The ims_pcu_reset_device() sysfs callback calls ims_pcu_execute_command()
without acquiring pcu->cmd_mutex. This can lead to data races and
corruption of the shared command buffer if triggered concurrently with
other commands.

Acquire pcu->cmd_mutex before calling ims_pcu_execute_command().

Fixes: 628329d52474 ("Input: add IMS Passenger Control Unit driver")
Cc: stable@vger.kernel.org
Reported-by: Sashiko bot <sashiko-bot@kernel.org>
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/input/misc/ims-pcu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
index 55d4fffda41bf2..94129af05620ea 100644
--- a/drivers/input/misc/ims-pcu.c
+++ b/drivers/input/misc/ims-pcu.c
@@ -1173,6 +1173,8 @@ static ssize_t ims_pcu_reset_device(struct device *dev,
 
 	dev_info(pcu->dev, "Attempting to reset device\n");
 
+	guard(mutex)(&pcu->cmd_mutex);
+
 	error = ims_pcu_execute_command(pcu, PCU_RESET, &reset_byte, 1);
 	if (error) {
 		dev_info(pcu->dev,
-- 
2.53.0