tree 737c3245af23ec8b4cb9a1e05062f30ca37e4cb3
parent d07a9cba6be5c0e947afc1014b5a62182a86f1f1
author Jussi Kivilinna <jussi.kivilinna@mbnet.fi> 1241741661 -0700
committer Dmitry Torokhov <dmitry.torokhov@gmail.com> 1241748256 -0700

Input: ff-memless - fix signed to unsigned bit overflow

When userspace sets effect->u.rumble.strong_magnitude to 0x8001 or
larger, ml_combine_effects() would always return strong_magnitude
0xffff.

Problem is that 'gain' is passed in as signed integer. Multiplying
magnitude (__u16) with gain (int) causes magnitude read as signed and
results negative value (with magnitude > 0x8000). This signed integer
is then divided and value, still negative, converted to 32bit unsigned
integer. Finally checking combine overflow min(new+old, 0xffff) gives
out 0xffff.

Fix is to simply change 'gain' to unsigned int.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Acked-by: Anssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>