diff options
| author | Nikita Zhandarovich <n.zhandarovich@fintech.ru> | 2025-01-16 05:48:01 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-25 10:47:57 +0200 |
| commit | b33386fabb2b78b56f1d97cf567f852f54f386ab (patch) | |
| tree | 0d2c8ccdae7dc654a973f03f4cf0beceae39bfcd | |
| parent | de67afd688085b710a5210a3d090daf07fe97ed7 (diff) | |
drm/repaper: fix integer overflows in repeat functions
commit 4d098000ac193f359e6b8ca4801dbdbd6a27b41f upstream.
There are conditions, albeit somewhat unlikely, under which right hand
expressions, calculating the end of time period in functions like
repaper_frame_fixed_repeat(), may overflow.
For instance, if 'factor10x' in repaper_get_temperature() is high
enough (170), as is 'epd->stage_time' in repaper_probe(), then the
resulting value of 'end' will not fit in unsigned int expression.
Mitigate this by casting 'epd->factored_stage_time' to wider type before
any multiplication is done.
Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.
Fixes: 3589211e9b03 ("drm/tinydrm: Add RePaper e-ink driver")
Cc: stable@vger.kernel.org
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Alex Lanzano <lanzano.alex@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250116134801.22067-1-n.zhandarovich@fintech.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpu/drm/tiny/repaper.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/repaper.c index 1f78aa3d26bb..768dfea15aec 100644 --- a/drivers/gpu/drm/tiny/repaper.c +++ b/drivers/gpu/drm/tiny/repaper.c @@ -455,7 +455,7 @@ static void repaper_frame_fixed_repeat(struct repaper_epd *epd, u8 fixed_value, enum repaper_stage stage) { u64 start = local_clock(); - u64 end = start + (epd->factored_stage_time * 1000 * 1000); + u64 end = start + ((u64)epd->factored_stage_time * 1000 * 1000); do { repaper_frame_fixed(epd, fixed_value, stage); @@ -466,7 +466,7 @@ static void repaper_frame_data_repeat(struct repaper_epd *epd, const u8 *image, const u8 *mask, enum repaper_stage stage) { u64 start = local_clock(); - u64 end = start + (epd->factored_stage_time * 1000 * 1000); + u64 end = start + ((u64)epd->factored_stage_time * 1000 * 1000); do { repaper_frame_data(epd, image, mask, stage); |