From cca80b973244cf7cf721b05b33178ba4826dbc5e Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 22 Feb 2010 06:45:07 -0300 Subject: [PATCH] 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 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/cx88/cx88-alsa.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/media/video/cx88/cx88-alsa.c b/drivers/media/video/cx88/cx88-alsa.c index 5a67445dd6ed..64b350df78e3 100644 --- a/drivers/media/video/cx88/cx88-alsa.c +++ b/drivers/media/video/cx88/cx88-alsa.c @@ -583,16 +583,18 @@ static int snd_cx88_volume_put(struct snd_kcontrol *kcontrol, { 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); -- 2.20.1