diff options
| author | Valery Borovsky <vebohr@gmail.com> | 2026-05-13 08:42:44 +0300 |
|---|---|---|
| committer | Hans Verkuil <hverkuil+cisco@kernel.org> | 2026-05-20 08:58:05 +0200 |
| commit | 906e410dcffbbd99fb4081abab817a830033aa28 (patch) | |
| tree | fc4317afd58c58ecd63f75ef6b2d5639166888f2 | |
| parent | e62bb5abdcc0dc57ff09c4db961784582e61cd9b (diff) | |
media: pwc: Drain fill_buf on start_streaming() failure
pwc_isoc_init() submits its isochronous URBs with
usb_submit_urb(.., GFP_KERNEL) in a loop. After the first URB is
submitted, its completion handler pwc_isoc_handler() can run on another
CPU before the loop finishes:
start_streaming()
pwc_isoc_init()
usb_submit_urb(urbs[0], GFP_KERNEL)
pwc_isoc_handler(urbs[0])
pdev->fill_buf =
pwc_get_next_fill_buf(pdev)
usb_submit_urb(urbs[i>0], ..) -> fails
pwc_isoc_cleanup(pdev) /* kills URBs */
return ret;
pwc_cleanup_queued_bufs(pdev, VB2_BUF_STATE_QUEUED)
pwc_get_next_fill_buf() detaches a buffer from pdev->queued_bufs and
stores it in pdev->fill_buf. The error path in start_streaming() only
drains pdev->queued_bufs, so the buffer parked in pdev->fill_buf is
leaked. vb2_start_streaming() then triggers
WARN_ON(owned_by_drv_count).
stop_streaming() already handles this since commit 80b0963e1698
("[media] pwc: fix WARN_ON"), which added the fill_buf drain in the
teardown path but not in the start_streaming() error path. Mirror that
handling on failure so start_streaming() returns with no buffer owned
by the driver.
Issue identified by automated review of the INV-003 series at
https://sashiko.dev/
Fixes: 885fe18f5542 ("[media] pwc: Replace private buffer management code with videobuf2")
Cc: stable@vger.kernel.org
Signed-off-by: Valery Borovsky <vebohr@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
| -rw-r--r-- | drivers/media/usb/pwc/pwc-if.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c index 59b99ac8fcb6..e2884b04d952 100644 --- a/drivers/media/usb/pwc/pwc-if.c +++ b/drivers/media/usb/pwc/pwc-if.c @@ -730,6 +730,11 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count) pwc_camera_power(pdev, 0); /* And cleanup any queued bufs!! */ pwc_cleanup_queued_bufs(pdev, VB2_BUF_STATE_QUEUED); + if (pdev->fill_buf) { + vb2_buffer_done(&pdev->fill_buf->vb.vb2_buf, + VB2_BUF_STATE_QUEUED); + pdev->fill_buf = NULL; + } } mutex_unlock(&pdev->v4l2_lock); |