Commit 72cafe63 authored by Andrey Shumilin's avatar Andrey Shumilin Committed by Takashi Iwai
Browse files

ALSA: firewire-lib: Avoid division by zero in apply_constraint_to_size() 



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 826b5de9
("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: 826b5de9 ("ALSA: firewire-lib: fix insufficient PCM rule for period/buffer size")
Signed-off-by: default avatarAndrey Shumilin <shum.sdl@nppct.ru>
Reviewed-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://patch.msgid.link/20241018060018.1189537-1-shum.sdl@nppct.ru


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 164cd0e0

sound/firewire/amdtp-stream.c

+3 −0
Original line number Diff line number Diff line
@@ -172,6 +172,9 @@ 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;