Patch "[media] vb2: core: Skip planes array verification if pb is NULL" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

[media] vb2: core: Skip planes array verification if pb is NULL

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
vb2-core-skip-planes-array-verification-if-pb-is-null.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Sakari Ailus <[email protected]>
Date: Wed, 11 May 2016 18:44:32 -0300
Subject: [media] vb2: core: Skip planes array verification if pb is NULL

From: Sakari Ailus <[email protected]>

commit 126f40298446a82116e1f92a1aaf72b8c8228fae upstream.

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.

---
 drivers/media/v4l2-core/videobuf2-core.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

@@ -1505,7 +1505,7 @@ static int __vb2_get_done_vb(struct vb2_
 			     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.

@@ -1521,10 +1521,12 @@ static int __vb2_get_done_vb(struct vb2_
 	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);

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/vb2-core-skip-planes-array-verification-if-pb-is-null.patch queue-4.4/videobuf2-v4l2-verify-planes-array-in-buffer-dequeueing.patch