linux-kernel - [PATCH] media: v4l2-flash: fix NULL dereference in v4l2_flash_s

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Date:   Wed,  7 Dec 2022 17:18:07 +0300
From:   Aleksandr Burakov <a.burakov@...alinux.ru>
To:     Mauro Carvalho Chehab <mchehab@...nel.org>
Cc:     Aleksandr Burakov <a.burakov@...alinux.ru>,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
        lvc-project@...uxtesting.org
Subject: [PATCH] media: v4l2-flash: fix NULL dereference in v4l2_flash_s_ctrl()

The NULL check added for fled_cdev before dereference.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Aleksandr Burakov <a.burakov@...alinux.ru>
Fixes: 42bd6f59ae90 ("media: Add registration helpers for V4L2 flash sub-devices")
---
 drivers/media/v4l2-core/v4l2-flash-led-class.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-flash-led-class.c b/drivers/media/v4l2-core/v4l2-flash-led-class.c
index 355595a0fefa..36cc46e80eea 100644
--- a/drivers/media/v4l2-core/v4l2-flash-led-class.c
+++ b/drivers/media/v4l2-core/v4l2-flash-led-class.c
@@ -291,12 +291,16 @@ static int v4l2_flash_s_ctrl(struct v4l2_ctrl *c)
 		 * No conversion is needed as LED Flash class also uses
 		 * microseconds for flash timeout units.
 		 */
+		if (!fled_cdev)
+			return -EINVAL;
 		return led_set_flash_timeout(fled_cdev, c->val);
 	case V4L2_CID_FLASH_INTENSITY:
 		/*
 		 * No conversion is needed as LED Flash class also uses
 		 * microamperes for flash intensity units.
 		 */
+		if (!fled_cdev)
+			return -EINVAL;
 		return led_set_flash_brightness(fled_cdev, c->val);
 	}
 
-- 
2.25.1