V4L/DVB: cx88-alsa: prevent out-of-range volume setting
Ensure that volume values are always in the allowed range. Otherwise,
it would be possible to set other bits in the AUD_VOL_CTL register or to
get a wrong sign in the AUD_BAL_CTL register.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/cx88/cx88-alsa.c b/drivers/media/video/cx88/cx88-alsa.c
index 5a67445..64b350d 100644
--- a/drivers/media/video/cx88/cx88-alsa.c
+++ b/drivers/media/video/cx88/cx88-alsa.c
@@ -583,16 +583,18 @@
{
snd_cx88_card_t *chip = snd_kcontrol_chip(kcontrol);
struct cx88_core *core=chip->core;
- int v, b;
+ int left, right, v, b;
int changed = 0;
u32 old;
- b = value->value.integer.value[1] - value->value.integer.value[0];
+ left = value->value.integer.value[0] & 0x3f;
+ right = value->value.integer.value[1] & 0x3f;
+ b = right - left;
if (b < 0) {
- v = 0x3f - value->value.integer.value[0];
+ v = 0x3f - left;
b = (-b) | 0x40;
} else {
- v = 0x3f - value->value.integer.value[1];
+ v = 0x3f - right;
}
/* Do we really know this will always be called with IRQs on? */
spin_lock_irq(&chip->reg_lock);