From 126f40298446a82116e1f92a1aaf72b8c8228fae Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 11 May 2016 18:44:32 -0300 Subject: [PATCH] [media] vb2: core: Skip planes array verification if pb is NULL An earlier patch fixing an input validation issue introduced another issue: vb2_core_dqbuf() is called with pb argument value NULL in some cases, causing a NULL pointer dereference. Fix this by skipping the verification as there's nothing to verify. Fixes: e7e0c3e26587 ("[media] videobuf2-core: Check user space planes array in dqbuf") Signed-off-by: David R Signed-off-by: Sakari Ailus Reviewed-by: Hans Verkuil Cc: stable@vger.kernel.org # for v4.4 and later Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/videobuf2-core.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 9fbcb67..633fc1a 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -1648,7 +1648,7 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, void *pb, int nonblocking) { unsigned long flags; - int ret; + int ret = 0; /* * Wait for at least one buffer to become available on the done_list. @@ -1664,10 +1664,12 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, spin_lock_irqsave(&q->done_lock, flags); *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); /* - * Only remove the buffer from done_list if v4l2_buffer can handle all - * the planes. + * Only remove the buffer from done_list if all planes can be + * handled. Some cases such as V4L2 file I/O and DVB have pb + * == NULL; skip the check then as there's nothing to verify. */ - ret = call_bufop(q, verify_planes_array, *vb, pb); + if (pb) + ret = call_bufop(q, verify_planes_array, *vb, pb); if (!ret) list_del(&(*vb)->done_entry); spin_unlock_irqrestore(&q->done_lock, flags); -- 2.7.4