From: Kees Cook <keescook@chromium.org>
To: Jaroslav Kysela <perex@perex.cz>
Cc: Kees Cook <keescook@chromium.org>, Takashi Iwai <tiwai@suse.com>,
alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
linux-hardening@vger.kernel.org
Subject: [PATCH] ALSA: lola: Bounds check loop iterator against streams array size
Date: Fri, 20 May 2022 09:55:37 -0700 [thread overview]
Message-ID: <20220520165537.2139826-1-keescook@chromium.org> (raw)
GCC 12 sees that it's technically possible for num_streams to be larger
than ARRAY_SIZE(pcm->streams). Bounds-check the iterator.
../sound/pci/lola/lola_pcm.c: In function 'lola_pcm_update':
../sound/pci/lola/lola_pcm.c:567:64: warning: array subscript [0, 31] is outside array bounds of 'struct lola_stream[16]' [-Warray-bounds]
567 | struct lola_stream *str = &pcm->streams[i];
| ~~~~~~~~~~~~^~~
In file included from ../sound/pci/lola/lola_pcm.c:15:
../sound/pci/lola/lola.h:307:28: note: while referencing 'streams'
307 | struct lola_stream streams[MAX_STREAM_COUNT];
| ^~~~~~~
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: alsa-devel@alsa-project.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
sound/pci/lola/lola_pcm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/lola/lola_pcm.c b/sound/pci/lola/lola_pcm.c
index 738ec987000a..32193fae978d 100644
--- a/sound/pci/lola/lola_pcm.c
+++ b/sound/pci/lola/lola_pcm.c
@@ -561,8 +561,9 @@ static snd_pcm_uframes_t lola_pcm_pointer(struct snd_pcm_substream *substream)
void lola_pcm_update(struct lola *chip, struct lola_pcm *pcm, unsigned int bits)
{
int i;
+ u8 num_streams = min_t(u8, pcm->num_streams, ARRAY_SIZE(pcm->streams));
- for (i = 0; bits && i < pcm->num_streams; i++) {
+ for (i = 0; bits && i < num_streams; i++) {
if (bits & (1 << i)) {
struct lola_stream *str = &pcm->streams[i];
if (str->substream && str->running)
--
2.32.0
next reply other threads:[~2022-05-20 16:55 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-20 16:55 Kees Cook [this message]
2022-05-21 6:49 ` [PATCH] ALSA: lola: Bounds check loop iterator against streams array size Takashi Iwai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220520165537.2139826-1-keescook@chromium.org \
--to=keescook@chromium.org \
--cc=alsa-devel@alsa-project.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=perex@perex.cz \
--cc=tiwai@suse.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox