Revert "media: v4l2-dev: fix error handling in __video_register_device()"

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This reverts commit 2a934fdb01.

The intentions of that patch were good, but it doesn't work.

The idea is that if device_register fails, you have to do a put_device
to let the ref counter release resources.

However, the V4L2 API says that if video_register_device() fails, then
you have to call video_device_release(), which kfree()s the video_device
struct.

But the put_device() will already have freed the struct, so you end
up in a double-free scenario.

There is not really a good way of fixing this without breaking
video_register_device() into two parts, one that initializes everything,
and one that does the actual device_register, and then converting all
V4L2 drivers to this new model.

That is a massive job, and it is very unlikely that device_register
will fail.

So rather than ending up in a double-free scenario, just revert this
patch, and in that case we'll have a small memory leak. Which is a lot
more robust.

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Fixes: 2a934fdb01 ("media: v4l2-dev: fix error handling in __video_register_device()")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-media/20260520090624.1071139-1-lgs201920130244@gmail.com/
Link: https://lore.kernel.org/all/2026042058-charm-storable-4ad8@gregkh/
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

...

This commit is contained in:

Hans Verkuil 2026-07-17 15:42:45 +02:00

parent aeaacc3001

commit e7600f5cee

1 changed files with 7 additions and 7 deletions

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drivers/media/v4l2-core/v4l2-dev.c

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