From: Hans Verkuil hverkuil-cisco@xs4all.nl
commit 6f51fdfd8229d5358c2d6e272cf73478866e8ddc upstream.
poll_wait uses &buf->done, but buf is NULL. Move the poll_wait to later in the function once buf is correctly set and only call it if it is non-NULL.
Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Reported-by: Dan Carpenter dan.carpenter@oracle.com Fixes: bb436cbeb918 ("media: videobuf: fix epoll() by calling poll_wait first") Cc: stable@vger.kernel.org # for v5.1 and up Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/v4l2-core/videobuf-core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/media/v4l2-core/videobuf-core.c +++ b/drivers/media/v4l2-core/videobuf-core.c @@ -1123,7 +1123,6 @@ __poll_t videobuf_poll_stream(struct fil struct videobuf_buffer *buf = NULL; __poll_t rc = 0;
- poll_wait(file, &buf->done, wait); videobuf_queue_lock(q); if (q->streaming) { if (!list_empty(&q->stream)) @@ -1143,7 +1142,9 @@ __poll_t videobuf_poll_stream(struct fil } buf = q->read_buf; } - if (!buf) + if (buf) + poll_wait(file, &buf->done, wait); + else rc = EPOLLERR;
if (0 == rc) {