[PATCH 1/1] v4l: ioctl: Validate num_planes for debug messages

* [PATCH 1/1] v4l: ioctl: Validate num_planes for debug messages
@ 2019-01-10 14:24 Sakari Ailus
  2019-01-10 15:42 ` Thierry Reding
       [not found] ` <20190116133554.E22672086D@mail.kernel.org>
  0 siblings, 2 replies; 3+ messages in thread
From: Sakari Ailus @ 2019-01-10 14:24 UTC (permalink / raw)
  To: linux-media; +Cc: hverkuil, Thierry Reding, Ezequiel Garcia

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@linux.intel.com>
Cc: stable@vger.kernel.org
---
 drivers/media/v4l2-core/v4l2-ioctl.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 3e57fa073b885..0e15b14055e5f 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -287,6 +287,7 @@ static void v4l_print_format(const void *arg, bool write_only)
 	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));
@@ -317,7 +318,8 @@ static void v4l_print_format(const void *arg, bool write_only)
 			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);
-- 
2.11.0


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