commit 4d098000ac 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: 3589211e9b ("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>
b33386fabb