[PATCH 5.15.y] media: zoran: Avoid freeing a registered video_device twice

[Sasha Levin <sashal@kernel.org>]

From: Ruoyu Wang <ruoyuw560@gmail.com>

[ Upstream commit 0735e0b5a96761a9ce277a238e834008ad92a0a5 ]

zoran_init_video_device() installs zoran_vdev_release() as the
video_device release callback through zoran_template. After
video_register_device() succeeds, video_unregister_device() drops the
registered video_device reference and the V4L2 core eventually invokes
that release callback, which kfree()s the video_device.

zoran_exit_video_devices() called video_unregister_device() and then
kfree(zr->video_dev), so device teardown could free the same
video_device twice.

Remove the direct kfree() and clear the cached pointer after
unregistering. The pre-registration failure path keeps its manual free
because the video_device was not registered there.

This issue was found by a static analysis checker and confirmed by
manual source review.

Fixes: 82e3a496eb56 ("media: staging: media: zoran: move videodev alloc")
Cc: stable@vger.kernel.org
Signed-off-by: Ruoyu Wang <ruoyuw560@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/staging/media/zoran/zoran_card.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/media/zoran/zoran_card.c b/drivers/staging/media/zoran/zoran_card.c
index 11d415c0c05d2..b6a9fef71ba2e 100644
--- a/drivers/staging/media/zoran/zoran_card.c
+++ b/drivers/staging/media/zoran/zoran_card.c
@@ -832,7 +832,7 @@ static int zoran_init_video_device(struct zoran *zr, struct video_device *video_
 static void zoran_exit_video_devices(struct zoran *zr)
 {
 	video_unregister_device(zr->video_dev);
-	kfree(zr->video_dev);
+	zr->video_dev = NULL;
 }
 
 static int zoran_init_video_devices(struct zoran *zr)
-- 
2.53.0