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| author | Jussi Kivilinna <jussi.kivilinna@mbnet.fi> | 2009-05-08 02:14:21 +0200 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-05-08 04:04:16 +0200 |
| commit | 9e68177ef93b2f34eee5a1e1707bceef4b9ba69c (patch) | |
| tree | 737c3245af23ec8b4cb9a1e05062f30ca37e4cb3 /drivers/input | |
| parent | Input: joydev - blacklist digitizers (diff) | |
| download | linux-9e68177ef93b2f34eee5a1e1707bceef4b9ba69c.tar.xz linux-9e68177ef93b2f34eee5a1e1707bceef4b9ba69c.zip | |
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>
Diffstat (limited to 'drivers/input')
| -rw-r--r-- | drivers/input/ff-memless.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c index bc4e40f3ede7..2d1415e16834 100644 --- a/drivers/input/ff-memless.c +++ b/drivers/input/ff-memless.c @@ -226,7 +226,7 @@ static int get_compatible_type(struct ff_device *ff, int effect_type) */ static void ml_combine_effects(struct ff_effect *effect, struct ml_effect_state *state, - int gain) + unsigned int gain) { struct ff_effect *new = state->effect; unsigned int strong, weak, i; |