(Changes since v2: dropped local variable as suggested by Laurent) Commit f035eb4e976ef5a059e30bc91cfd310ff030a7d3 (videobuf2: fix lockdep warning) unfortunately removed the mmap_sem lock that is needed around the call to __qbuf_userptr. Amazingly nobody noticed this (especially me as the author) until Jan Kara pointed this out to me. Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> Reported-by: Jan Kara <jack@xxxxxxx> Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> --- drivers/media/v4l2-core/videobuf2-core.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 5b808e2..ce59962b 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -1627,7 +1627,9 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) ret = __qbuf_mmap(vb, b); break; case V4L2_MEMORY_USERPTR: + down_read(¤t->mm->mmap_sem); ret = __qbuf_userptr(vb, b); + up_read(¤t->mm->mmap_sem); break; case V4L2_MEMORY_DMABUF: ret = __qbuf_dmabuf(vb, b); -- 2.1.0.rc1 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html