[PATCH 4.20 056/111] media: v4l: ioctl: Validate num_planes for debug messages

From: Greg Kroah-Hartman
Date: Mon Jan 21 2019 - 08:48:31 EST


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

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

From: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>

commit 7fe9f01c04c2673bd6662c35b664f0f91888b96f upstream.

The num_planes field in struct v4l2_pix_format_mplane is used in a loop
before validating it. As the use is printing a debug message in this case,
just cap the value to the maximum allowed.

Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # for v4.12 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/media/v4l2-core/v4l2-ioctl.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -286,6 +286,7 @@ static void v4l_print_format(const void
const struct v4l2_window *win;
const struct v4l2_sdr_format *sdr;
const struct v4l2_meta_format *meta;
+ u32 planes;
unsigned i;

pr_cont("type=%s", prt_names(p->type, v4l2_type_names));
@@ -316,7 +317,8 @@ static void v4l_print_format(const void
prt_names(mp->field, v4l2_field_names),
mp->colorspace, mp->num_planes, mp->flags,
mp->ycbcr_enc, mp->quantization, mp->xfer_func);
- for (i = 0; i < mp->num_planes; i++)
+ planes = min_t(u32, mp->num_planes, VIDEO_MAX_PLANES);
+ for (i = 0; i < planes; i++)
printk(KERN_DEBUG "plane %u: bytesperline=%u sizeimage=%u\n", i,
mp->plane_fmt[i].bytesperline,
mp->plane_fmt[i].sizeimage);