This is a note to let you know that I've just added the patch titled
ALSA: firewire-lib: Avoid division by zero in apply_constraint_to_size()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-firewire-lib-avoid-division-by-zero-in-apply_co.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit af61aa7d87bd0d01cb6ca08c32fe55e1db3e1523
Author: Andrey Shumilin <shum.sdl@xxxxxxxx>
Date: Fri Oct 18 09:00:18 2024 +0300
ALSA: firewire-lib: Avoid division by zero in apply_constraint_to_size()
[ Upstream commit 72cafe63b35d06b5cfbaf807e90ae657907858da ]
The step variable is initialized to zero. It is changed in the loop,
but if it's not changed it will remain zero. Add a variable check
before the division.
The observed behavior was introduced by commit 826b5de90c0b
("ALSA: firewire-lib: fix insufficient PCM rule for period/buffer size"),
and it is difficult to show that any of the interval parameters will
satisfy the snd_interval_test() condition with data from the
amdtp_rate_table[] table.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 826b5de90c0b ("ALSA: firewire-lib: fix insufficient PCM rule for period/buffer size")
Signed-off-by: Andrey Shumilin <shum.sdl@xxxxxxxx>
Reviewed-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
Link: https://patch.msgid.link/20241018060018.1189537-1-shum.sdl@xxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 7a282d8e71485..bd272ab2048e4 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -163,6 +163,9 @@ static int apply_constraint_to_size(struct snd_pcm_hw_params *params,
step = max(step, amdtp_syt_intervals[i]);
}
+ if (step == 0)
+ return -EINVAL;
+
t.min = roundup(s->min, step);
t.max = rounddown(s->max, step);
t.integer = 1;
