[PATCH 4.19 67/88] ALSA: pcm: oss: Remove superfluous WARN_ON() for mulaw sanity check

From: Greg Kroah-Hartman
Date: Tue Sep 08 2020 - 14:32:59 EST

From: Takashi Iwai <tiwai@xxxxxxx>

commit 949a1ebe8cea7b342085cb6a4946b498306b9493 upstream.

The PCM OSS mulaw plugin has a check of the format of the counter part
whether it's a linear format. The check is with snd_BUG_ON() that
emits WARN_ON() when the debug config is set, and it confuses
syzkaller as if it were a serious issue. Let's drop snd_BUG_ON() for
avoiding that.

While we're at it, correct the error code to a more suitable, EINVAL.

Reported-by: syzbot+23b22dc2e0b81cbfcc95@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200901131802.18157-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

sound/core/oss/mulaw.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/core/oss/mulaw.c
+++ b/sound/core/oss/mulaw.c
@@ -329,8 +329,8 @@ int snd_pcm_plugin_build_mulaw(struct sn
return -EINVAL;
- if (snd_BUG_ON(!snd_pcm_format_linear(format->format)))
- return -ENXIO;
+ if (!snd_pcm_format_linear(format->format))
+ return -EINVAL;

err = snd_pcm_plugin_build(plug, "Mu-Law<->linear conversion",
src_format, dst_format,