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authorTakashi Iwai <tiwai@suse.de>2020-07-17 11:40:23 +0300
committerTakashi Iwai <tiwai@suse.de>2020-07-17 11:59:38 +0300
commit60379ba08532eca861e933b389526a4dc89e0c42 (patch)
tree58ead02f090f3fcd15a4a91c2e9bc110fe8bda05
parent5734e509d5d515c187f642937ef2de1e58d7715d (diff)
downloadlinux-60379ba08532eca861e933b389526a4dc89e0c42.tar.xz
ALSA: info: Drop WARN_ON() from buffer NULL sanity check
snd_info_get_line() has a sanity check of NULL buffer -- both buffer itself being NULL and buffer->buffer being NULL. Basically both checks are valid and necessary, but the problem is that it's with snd_BUG_ON() macro that triggers WARN_ON(). The latter condition (NULL buffer->buffer) can be met arbitrarily by user since the buffer is allocated at the first write, so it means that user can trigger WARN_ON() at will. This patch addresses it by simply moving buffer->buffer NULL check out of snd_BUG_ON() so that spurious WARNING is no longer triggered. Reported-by: syzbot+e42d0746c3c3699b6061@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200717084023.5928-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--sound/core/info.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/core/info.c b/sound/core/info.c
index 8c6bc5241df5..9fec3070f8ba 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -606,7 +606,9 @@ int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len)
{
int c;
- if (snd_BUG_ON(!buffer || !buffer->buffer))
+ if (snd_BUG_ON(!buffer))
+ return 1;
+ if (!buffer->buffer)
return 1;
if (len <= 0 || buffer->stop || buffer->error)
return 1;