media: videobuf2: forbid remove_bufs when legacy fileio is active

commit 27afd6e066cfd80ddbe22a4a11b99174ac89cced upstream.

vb2_ioctl_remove_bufs() call manipulates queue internal buffer list,
potentially overwriting some pointers used by the legacy fileio access
mode. Forbid that ioctl when fileio is active to protect internal queue
state between subsequent read/write calls.

CC: stable@vger.kernel.org
Fixes: a3293a85381e ("media: v4l2: Add REMOVE_BUFS ioctl")
Reported-by: Shuangpeng Bai <SJB7183@psu.edu>
Closes: https://lore.kernel.org/linux-media/5317B590-AAB4-4F17-8EA1-621965886D49@psu.edu/
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 1cd26faee50338aefeb670c6865da7c2d43f44d3..b768b6ad996885e015d1a9addee01aa063b01b8e 100644 (file)
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -1014,6 +1014,11 @@ int vb2_ioctl_remove_bufs(struct file *file, void *priv,
        if (vb2_queue_is_busy(vdev->queue, file))
                return -EBUSY;
 
+       if (vb2_fileio_is_active(vdev->queue)) {
+               dprintk(vdev->queue, 1, "file io in progress\n");
+               return -EBUSY;
+       }
+
        return vb2_core_remove_bufs(vdev->queue, d->index, d->count);
 }
 EXPORT_SYMBOL_GPL(vb2_ioctl_remove_bufs);