github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-28 01:55:51 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

media: msi2500: Return queued buffers on start_streaming() failure

Browse Source 
The vb2 framework hands buffers to the driver via buf_queue() before
calling start_streaming().  If start_streaming() returns an error
without first returning those buffers via vb2_buffer_done(),
vb2_start_streaming() fires WARN_ON(owned_by_drv_count) and the queued
buffers leak.

msi2500_start_streaming() had five error paths that all hit this trap
and were further tangled by ret-overwriting between calls:

  - -ENODEV when the USB device was already disconnected
  - -ERESTARTSYS when mutex_lock_interruptible() was interrupted
  - msi2500_set_usb_adc() failure: ret was silently overwritten by
    the next call (msi2500_isoc_init), so the error was lost entirely
  - msi2500_isoc_init() failure: cleanup_queued_bufs was called, but
    the function then fell through to msi2500_ctrl_msg() and again
    masked the original error by overwriting ret
  - msi2500_ctrl_msg(CMD_START_STREAMING) failure: no cleanup at all,
    leaving isoc URBs submitted with no way for the driver to consume
    them

Consolidate the error paths into a small goto chain.  Every failure
now stops the function, drains the queued-buffer list, and returns
the real error code.  The ctrl_msg failure path also rolls back the
preceding msi2500_isoc_init() via msi2500_isoc_cleanup() before
unlocking and draining.

The cleanup helper takes a vb2_buffer_state argument so that the
start_streaming error paths can pass VB2_BUF_STATE_QUEUED (as
expected by userspace on start_streaming failure) while stop_streaming
keeps its existing VB2_BUF_STATE_ERROR semantics.

This mirrors the uvcvideo fix in commit 4cf3b6fd54 ("media: uvcvideo:
Return queued buffers on start_streaming() failure").

Fixes: 977e444f59 ("[media] Mirics MSi3101 SDR Dongle driver")
Cc: stable@vger.kernel.org
Signed-off-by: Valery Borovsky <vebohr@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
This commit is contained in:
Valery Borovsky 2026-05-11 20:12:07 +03:00 committed by Hans Verkuil
parent 04344d0b49
commit 7201c17786
1 changed files with 24 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
drivers/media/usb/msi2500/msi2500.c
View File

@ -541,7 +541,8 @@ static int msi2500_isoc_init(struct msi2500_dev *dev)
}
/* Must be called with vb_queue_lock hold */
static void msi2500_cleanup_queued_bufs(struct msi2500_dev *dev)
static void msi2500_cleanup_queued_bufs(struct msi2500_dev *dev,
enum vb2_buffer_state state)
{
unsigned long flags;
@ -554,7 +555,7 @@ static void msi2500_cleanup_queued_bufs(struct msi2500_dev *dev)
buf = list_entry(dev->queued_bufs.next,
struct msi2500_frame_buf, list);
list_del(&buf->list);
vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR);
vb2_buffer_done(&buf->vb.vb2_buf, state);
}
spin_unlock_irqrestore(&dev->queued_bufs_lock, flags);
}
@ -830,25 +831,40 @@ static int msi2500_start_streaming(struct vb2_queue *vq, unsigned int count)
dev_dbg(dev->dev, "\n");
if (!dev->udev)
return -ENODEV;
if (!dev->udev) {
ret = -ENODEV;
goto err_cleanup;
}
if (mutex_lock_interruptible(&dev->v4l2_lock))
return -ERESTARTSYS;
if (mutex_lock_interruptible(&dev->v4l2_lock)) {
ret = -ERESTARTSYS;
goto err_cleanup;
}
/* wake-up tuner */
v4l2_subdev_call(dev->v4l2_subdev, core, s_power, 1);
ret = msi2500_set_usb_adc(dev);
if (ret)
goto err_unlock_cleanup;
ret = msi2500_isoc_init(dev);
if (ret)
msi2500_cleanup_queued_bufs(dev);
goto err_unlock_cleanup;
ret = msi2500_ctrl_msg(dev, CMD_START_STREAMING, 0);
if (ret)
goto err_isoc_cleanup;
mutex_unlock(&dev->v4l2_lock);
return 0;
err_isoc_cleanup:
msi2500_isoc_cleanup(dev);
err_unlock_cleanup:
mutex_unlock(&dev->v4l2_lock);
err_cleanup:
msi2500_cleanup_queued_bufs(dev, VB2_BUF_STATE_QUEUED);
return ret;
}
@ -863,7 +879,7 @@ static void msi2500_stop_streaming(struct vb2_queue *vq)
if (dev->udev)
msi2500_isoc_cleanup(dev);
msi2500_cleanup_queued_bufs(dev);
msi2500_cleanup_queued_bufs(dev, VB2_BUF_STATE_ERROR);
/* according to tests, at least 700us delay is required */
msleep(20);