[PATCH 4.14 19/89] ALSA: pcm: Remove yet superfluous WARN_ON()

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

--

From: Takashi Iwai 

commit 23b19b7b50fe1867da8d431eea9cd3e4b6328c2c upstream.

muldiv32() contains a snd_BUG_ON() (which is morphed as WARN_ON() with
debug option) for checking the case of 0 / 0.  This would be helpful
if this happens only as a logical error; however, since the hw refine
is performed with any data set provided by user, the inconsistent
values that can trigger such a condition might be passed easily.
Actually, syzbot caught this by passing some zero'ed old hw_params
ioctl.

So, having snd_BUG_ON() there is simply superfluous and rather
harmful to give unnecessary confusions.  Let's get rid of it.

Reported-by: syzbot+7e6ee55011deeebce...@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman 

---
 sound/core/pcm_lib.c |1 -
 1 file changed, 1 deletion(-)

--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -560,7 +560,6 @@ static inline unsigned int muldiv32(unsi
 {
u_int64_t n = (u_int64_t) a * b;
if (c == 0) {
-   snd_BUG_ON(!n);
*r = 0;
return UINT_MAX;
}

[PATCH 4.14 19/89] ALSA: pcm: Remove yet superfluous WARN_ON()

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

--

From: Takashi Iwai 

commit 23b19b7b50fe1867da8d431eea9cd3e4b6328c2c upstream.

muldiv32() contains a snd_BUG_ON() (which is morphed as WARN_ON() with
debug option) for checking the case of 0 / 0.  This would be helpful
if this happens only as a logical error; however, since the hw refine
is performed with any data set provided by user, the inconsistent
values that can trigger such a condition might be passed easily.
Actually, syzbot caught this by passing some zero'ed old hw_params
ioctl.

So, having snd_BUG_ON() there is simply superfluous and rather
harmful to give unnecessary confusions.  Let's get rid of it.

Reported-by: syzbot+7e6ee55011deeebce...@syzkaller.appspotmail.com
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman 

---
 sound/core/pcm_lib.c |1 -
 1 file changed, 1 deletion(-)

--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -560,7 +560,6 @@ static inline unsigned int muldiv32(unsi
 {
u_int64_t n = (u_int64_t) a * b;
if (c == 0) {
-   snd_BUG_ON(!n);
*r = 0;
return UINT_MAX;
}