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.
Signed-off-by: David R <david@xxxxxxxxxxxxxxx>
Use if () instead of ? :; it's nicer that way. Improve the comment in the
code as well.
Fixes: e7e0c3e26587 ("[media] videobuf2-core: Check user space planes array in dqbuf")
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # for v4.4 and later
---
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);
--
2.1.4
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