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 Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- v4: - got back to simple vb2_fileio_is_active() check as in v1, as relying on vb2_verify_memory_type() misses some corner cases important to v4l2 compliance
v3: https://lore.kernel.org/all/20251023113052.1303082-1-m.szyprowski@samsung.co... - moved vb2_verify_memory_type() check after (d->count == 0) check to pass v4l2 compliance
v2: https://lore.kernel.org/all/20251020160121.1985354-1-m.szyprowski@samsung.co... - dropped a change to vb2_ioctl_create_bufs(), as it is already handled by the vb2_verify_memory_type() call - replaced queue->type check in vb2_ioctl_remove_bufs() by a call to vb2_verify_memory_type() which covers all cases
v1: https://lore.kernel.org/all/20251016111154.993949-1-m.szyprowski@samsung.com... --- drivers/media/common/videobuf2/videobuf2-v4l2.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index d911021c1bb0..83862d57b126 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -1010,6 +1010,11 @@ 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);