[PATCH 4.4 110/163] [media] videobuf2-core: Check user space planes array in dqbuf

From: Greg Kroah-Hartman
Date: Mon May 02 2016 - 21:36:50 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>

commit e7e0c3e26587749b62d17b9dd0532874186c77f7 upstream.

The number of planes in videobuf2 is specific to a buffer. In order to
verify that the planes array provided by the user is long enough, a new
vb2_buf_op is required.

Call __verify_planes_array() when the dequeued buffer is known. Return an
error to the caller if there was one, otherwise remove the buffer from the
done list.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/media/v4l2-core/videobuf2-core.c | 10 +++++-----
include/media/videobuf2-core.h | 1 +
2 files changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1502,7 +1502,7 @@ static int __vb2_wait_for_done_vb(struct
* Will sleep if required for nonblocking == false.
*/
static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
- int nonblocking)
+ void *pb, int nonblocking)
{
unsigned long flags;
int ret;
@@ -1523,10 +1523,10 @@ static int __vb2_get_done_vb(struct vb2_
/*
* Only remove the buffer from done_list if v4l2_buffer can handle all
* the planes.
- * Verifying planes is NOT necessary since it already has been checked
- * before the buffer is queued/prepared. So it can never fail.
*/
- list_del(&(*vb)->done_entry);
+ ret = call_bufop(q, verify_planes_array, *vb, pb);
+ if (!ret)
+ list_del(&(*vb)->done_entry);
spin_unlock_irqrestore(&q->done_lock, flags);

return ret;
@@ -1604,7 +1604,7 @@ int vb2_core_dqbuf(struct vb2_queue *q,
struct vb2_buffer *vb = NULL;
int ret;

- ret = __vb2_get_done_vb(q, &vb, nonblocking);
+ ret = __vb2_get_done_vb(q, &vb, pb, nonblocking);
if (ret < 0)
return ret;

--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -363,6 +363,7 @@ struct vb2_ops {
};

struct vb2_buf_ops {
+ int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
int (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
struct vb2_plane *planes);