media: video-i2c: fix kthread error pointer left in kthread_vid_cap on failure

kthread_run() returns an ERR_PTR on failure, not NULL.
When start_streaming() fails, data->kthread_vid_cap is left holding
this error pointer instead of being cleared.

This causes two subsequent bugs:
1. A future call to start_streaming() sees a non-NULL kthread_vid_cap
   and returns 0 (success) immediately, without actually starting the
   capture thread.
2. A call to stop_streaming() checks 'kthread_vid_cap == NULL' which
   is false for an error pointer, and proceeds to call kthread_stop()
   on the error pointer, leading to a kernel crash.

Fix this by resetting kthread_vid_cap to NULL on failure before
jumping to the error path.

Fixes: 5cebaac609 ("media: video-i2c: add video-i2c driver")
Cc: stable@vger.kernel.org
Signed-off-by: Uday Khare <udaykhare77@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
This commit is contained in:
Uday Khare 2026-07-06 20:58:33 +05:30 • committed by Hans Verkuil
commit 76e379754b