[PATCH 4.4 54/74] ALSA: hdspm: Fix zero-division

Greg Kroah-Hartman
2016-03-08T00:11:06Z

From: Takashi Iwai <tiwai@suse.de>

commit c1099c3294c2344110085a38c50e478a5992b368 upstream.

HDSPM driver contains a code issuing zero-division potentially in
system sample rate ctl code. This patch fixes it by not processing
a zero or invalid rate value as a divisor, as well as excluding the
invalid value to be passed via the given ctl element.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/pci/rme9652/hdspm.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/sound/pci/rme9652/hdspm.c
+++ b/sound/pci/rme9652/hdspm.c
@@ -1601,6 +1601,9 @@ static void hdspm_set_dds_value(struct h
{
u64 n;

+ if (snd_BUG_ON(rate <= 0))
+ return;
+
if (rate >= 112000)
rate /= 4;
else if (rate >= 56000)
@@ -2215,6 +2218,8 @@ static int hdspm_get_system_sample_rate(
} else {
/* slave mode, return external sample rate */
rate = hdspm_external_sample_rate(hdspm);
+ if (!rate)
+ rate = hdspm->system_sample_rate;
}
}

@@ -2260,7 +2265,10 @@ static int snd_hdspm_put_system_sample_r
ucontrol)
{
struct hdspm *hdspm = snd_kcontrol_chip(kcontrol);
+ int rate = ucontrol->value.integer.value[0];

+ if (rate < 27000 || rate > 207000)
+ return -EINVAL;
hdspm_set_dds_value(hdspm, ucontrol->value.integer.value[0]);
return 0;
}