[PATCH v2] media: aspeed: Fix memory overwrite if timing is 1600x900

From: Jammy Huang
Date: Mon Jul 17 2023 - 05:51:26 EST


When capturing 1600x900, system could crash when system memory usage is
tight.

The way to reproduce this issue:
1. Use 1600x900 to display on host
2. Mount ISO through 'Virtual media' on OpenBMC's web
3. Run script as below on host to do sha continuously
#!/bin/bash
while [ [1] ];
do
find /media -type f -printf '"%h/%f"\n' | xargs sha256sum
done
4. Open KVM on OpenBMC's web

The size of macro block captured is 8x8. Therefore, we should make sure
the height of src-buf is 8 aligned to fix this issue.

Signed-off-by: Jammy Huang <jammy_huang@xxxxxxxxxxxxxx>
---
v2 changes
- Add how to reproduce this issue.
---
drivers/media/platform/aspeed/aspeed-video.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/aspeed/aspeed-video.c b/drivers/media/platform/aspeed/aspeed-video.c
index 374eb7781936..14594f55a77f 100644
--- a/drivers/media/platform/aspeed/aspeed-video.c
+++ b/drivers/media/platform/aspeed/aspeed-video.c
@@ -1130,7 +1130,7 @@ static void aspeed_video_get_resolution(struct aspeed_video *video)
static void aspeed_video_set_resolution(struct aspeed_video *video)
{
struct v4l2_bt_timings *act = &video->active_timings;
- unsigned int size = act->width * act->height;
+ unsigned int size = act->width * ALIGN(act->height, 8);

/* Set capture/compression frame sizes */
aspeed_video_calc_compressed_size(video, size);
@@ -1147,7 +1147,7 @@ static void aspeed_video_set_resolution(struct aspeed_video *video)
u32 width = ALIGN(act->width, 64);

aspeed_video_write(video, VE_CAP_WINDOW, width << 16 | act->height);
- size = width * act->height;
+ size = width * ALIGN(act->height, 8);
} else {
aspeed_video_write(video, VE_CAP_WINDOW,
act->width << 16 | act->height);

base-commit: 2605e80d3438c77190f55b821c6575048c68268e
--
2.25.1