[alsa-devel] [patch] sound: oss/sb_audio: cap value in sb201_audio_set_speed()

Dan Carpenter dan.carpenter at oracle.com
Sat Nov 17 16:08:57 CET 2012


We set "s" before we have capped "speed" so it could be the wrong value.
This could lead to a divide by zero bug.

Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
---
I fixed a similar bug in this file in Aug.  I'm not sure how I missed
this one.  I don't see any others I missed.

diff --git a/sound/oss/sb_audio.c b/sound/oss/sb_audio.c
index b2b3c01..048439a 100644
--- a/sound/oss/sb_audio.c
+++ b/sound/oss/sb_audio.c
@@ -442,7 +442,7 @@ static int sb201_audio_set_speed(int dev, int speed)
 {
 	sb_devc *devc = audio_devs[dev]->devc;
 	int tmp;
-	int s = speed * devc->channels;
+	int s;
 
 	if (speed > 0)
 	{
@@ -452,6 +452,7 @@ static int sb201_audio_set_speed(int dev, int speed)
 			speed = 44100;
 		if (devc->opened & OPEN_READ && speed > 15000)
 			speed = 15000;
+		s = speed * devc->channels;
 		devc->tconst = (256 - ((1000000 + s / 2) / s)) & 0xff;
 		tmp = 256 - devc->tconst;
 		speed = ((1000000 + tmp / 2) / tmp) / devc->channels;


More information about the Alsa-devel mailing list