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media: vivid: fix buffer overwrite when using > 32 buffers

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The maximum number of buffers that can be requested was increased to
64 for the video capture queue. But video capture used a must_blank
array that was still sized for 32 (VIDEO_MAX_FRAME). This caused an
out-of-bounds write when using buffer indices >= 32.

Create a new define MAX_VID_CAP_BUFFERS that is used to access the
must_blank array and set max_num_buffers for the video capture queue.

This solves a crash reported by:

	https://bugzilla.kernel.org/show_bug.cgi?id=219258

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Fixes: cea70ed416 ("media: test-drivers: vivid: Increase max supported buffers for capture queues")
Cc: stable@vger.kernel.org
This commit is contained in:
Hans Verkuil 2024-10-24 10:21:30 +02:00
parent ba9cf6b430
commit 96d8569563
4 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/media/test-drivers/vivid/vivid-core.c
View File

@ -910,7 +910,7 @@ static int vivid_create_queue(struct vivid_dev *dev,
* videobuf2-core.c to MAX_BUFFER_INDEX.
*/
if (buf_type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
q->max_num_buffers = 64;
q->max_num_buffers = MAX_VID_CAP_BUFFERS;
if (buf_type == V4L2_BUF_TYPE_SDR_CAPTURE)
q->max_num_buffers = 1024;
if (buf_type == V4L2_BUF_TYPE_VBI_CAPTURE)

4
drivers/media/test-drivers/vivid/vivid-core.h
View File

@ -26,6 +26,8 @@
#define MAX_INPUTS 16
/* The maximum number of outputs */
#define MAX_OUTPUTS 16
/* The maximum number of video capture buffers */
#define MAX_VID_CAP_BUFFERS 64
/* The maximum up or down scaling factor is 4 */
#define MAX_ZOOM 4
/* The maximum image width/height are set to 4K DMT */
@ -481,7 +483,7 @@ struct vivid_dev {
/* video capture */
struct tpg_data tpg;
unsigned ms_vid_cap;
bool must_blank[VIDEO_MAX_FRAME];
bool must_blank[MAX_VID_CAP_BUFFERS];
const struct vivid_fmt *fmt_cap;
struct v4l2_fract timeperframe_vid_cap;

2
drivers/media/test-drivers/vivid/vivid-ctrls.c
View File

@ -553,7 +553,7 @@ static int vivid_vid_cap_s_ctrl(struct v4l2_ctrl *ctrl)
break;
case VIVID_CID_PERCENTAGE_FILL:
tpg_s_perc_fill(&dev->tpg, ctrl->val);
for (i = 0; i < VIDEO_MAX_FRAME; i++)
for (i = 0; i < MAX_VID_CAP_BUFFERS; i++)
dev->must_blank[i] = ctrl->val < 100;
break;
case VIVID_CID_INSERT_SAV:

2
drivers/media/test-drivers/vivid/vivid-vid-cap.c
View File

@ -213,7 +213,7 @@ static int vid_cap_start_streaming(struct vb2_queue *vq, unsigned count)
dev->vid_cap_seq_count = 0;
dprintk(dev, 1, "%s\n", __func__);
for (i = 0; i < VIDEO_MAX_FRAME; i++)
for (i = 0; i < MAX_VID_CAP_BUFFERS; i++)
dev->must_blank[i] = tpg_g_perc_fill(&dev->tpg) < 100;
if (dev->start_streaming_error) {
dev->start_streaming_error = false;