[PATCH 3.16 009/217] [media] media: v4l2-compat-ioctl32: fix missing length copy in put_v4l2_buffer32

[Ben Hutchings]

3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Tiffany Lin <tiffany.lin@xxxxxxxxxxxx>

commit 7df5ab8774aa383c6d2bff00688d004585d96dfd upstream.

In v4l2-compliance utility, test QUERYBUF required correct length
value to go through each planar to check planar's length in
multi-planar buffer type

Signed-off-by: Tiffany Lin <tiffany.lin@xxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -392,7 +392,8 @@ static int get_v4l2_buffer32(struct v4l2
 		get_user(kp->index, &up->index) ||
 		get_user(kp->type, &up->type) ||
 		get_user(kp->flags, &up->flags) ||
-		get_user(kp->memory, &up->memory))
+		get_user(kp->memory, &up->memory) ||
+		get_user(kp->length, &up->length))
 			return -EFAULT;
 
 	if (V4L2_TYPE_IS_OUTPUT(kp->type))
@@ -404,9 +405,6 @@ static int get_v4l2_buffer32(struct v4l2
 			return -EFAULT;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(kp->type)) {
-		if (get_user(kp->length, &up->length))
-			return -EFAULT;
-
 		num_planes = kp->length;
 		if (num_planes == 0) {
 			kp->m.planes = NULL;
@@ -439,16 +437,14 @@ static int get_v4l2_buffer32(struct v4l2
 	} else {
 		switch (kp->memory) {
 		case V4L2_MEMORY_MMAP:
-			if (get_user(kp->length, &up->length) ||
-				get_user(kp->m.offset, &up->m.offset))
+			if (get_user(kp->m.offset, &up->m.offset))
 				return -EFAULT;
 			break;
 		case V4L2_MEMORY_USERPTR:
 			{
 			compat_long_t tmp;
 
-			if (get_user(kp->length, &up->length) ||
-			    get_user(tmp, &up->m.userptr))
+			if (get_user(tmp, &up->m.userptr))
 				return -EFAULT;
 
 			kp->m.userptr = (unsigned long)compat_ptr(tmp);
@@ -490,7 +486,8 @@ static int put_v4l2_buffer32(struct v4l2
 		copy_to_user(&up->timecode, &kp->timecode, sizeof(struct v4l2_timecode)) ||
 		put_user(kp->sequence, &up->sequence) ||
 		put_user(kp->reserved2, &up->reserved2) ||
-		put_user(kp->reserved, &up->reserved))
+		put_user(kp->reserved, &up->reserved) ||
+		put_user(kp->length, &up->length))
 			return -EFAULT;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(kp->type)) {
@@ -513,13 +510,11 @@ static int put_v4l2_buffer32(struct v4l2
 	} else {
 		switch (kp->memory) {
 		case V4L2_MEMORY_MMAP:
-			if (put_user(kp->length, &up->length) ||
-				put_user(kp->m.offset, &up->m.offset))
+			if (put_user(kp->m.offset, &up->m.offset))
 				return -EFAULT;
 			break;
 		case V4L2_MEMORY_USERPTR:
-			if (put_user(kp->length, &up->length) ||
-				put_user(kp->m.userptr, &up->m.userptr))
+			if (put_user(kp->m.userptr, &up->m.userptr))
 				return -EFAULT;
 			break;
 		case V4L2_MEMORY_OVERLAY: