diff options
| author | Nikita Zhandarovich <n.zhandarovich@fintech.ru> | 2025-01-16 05:48:01 -0800 |
|---|---|---|
| committer | Alex Lanzano <lanzano.alex@gmail.com> | 2025-02-24 19:43:23 -0500 |
| commit | 4d098000ac193f359e6b8ca4801dbdbd6a27b41f (patch) | |
| tree | fdeb986599a163349c198ffb9fa5eda2c89963f0 | |
| parent | ed531feda7852de0aa702fbe3d23a0f743ccc77b (diff) | |
drm/repaper: fix integer overflows in repeat functions
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
| -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 52ba6c699bc8..5c3b51eb0a97 100644 --- a/drivers/gpu/drm/tiny/repaper.c +++ b/drivers/gpu/drm/tiny/repaper.c @@ -456,7 +456,7 @@ 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); @@ -467,7 +467,7 @@ 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); |