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| author | Takashi Iwai <tiwai@suse.de> | 2020-07-17 11:40:23 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-29 08:42:52 +0300 |
| commit | ac27bfe94f5338c34f185c9bb68d58bfb60caad1 (patch) | |
| tree | 6b6a417c76e26c1d059d1c5e453190953a302553 | |
| parent | ac76becc7532cf57c77cbf7db5eb6ad09848900e (diff) | |
| download | linux-ac27bfe94f5338c34f185c9bb68d58bfb60caad1.tar.xz | |
ALSA: info: Drop WARN_ON() from buffer NULL sanity check
commit 60379ba08532eca861e933b389526a4dc89e0c42 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | sound/core/info.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/core/info.c b/sound/core/info.c index 5fb00437507b..f15569cd124d 100644 --- a/sound/core/info.c +++ b/sound/core/info.c @@ -634,7 +634,9 @@ int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len) { int c = -1; - 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; |