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ALSA: pcm: oss: Fix a few more UBSAN fixes

There are a few places that call round{up|down}_pow_of_two() with the
value zero, and this causes undefined behavior warnings.  Avoid
calling those macros if such a nonsense value is passed; it's a minor
optimization as well, as we handle it as either an error or a value to
be skipped, instead.

Reported-by: syzbot+33ef0b6639a8d2d42b4c@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201218161730.26596-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
zero-sugar-mainline-defconfig
Takashi Iwai 2020-12-18 17:17:30 +01:00
parent 618de0f4ef
commit 11cb881bf0
1 changed files with 14 additions and 8 deletions

View File

@ -693,6 +693,8 @@ static int snd_pcm_oss_period_size(struct snd_pcm_substream *substream,
oss_buffer_size = snd_pcm_plug_client_size(substream,
snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, NULL)) * oss_frame_size;
if (!oss_buffer_size)
return -EINVAL;
oss_buffer_size = rounddown_pow_of_two(oss_buffer_size);
if (atomic_read(&substream->mmap_count)) {
if (oss_buffer_size > runtime->oss.mmap_bytes)
@ -728,17 +730,21 @@ static int snd_pcm_oss_period_size(struct snd_pcm_substream *substream,
min_period_size = snd_pcm_plug_client_size(substream,
snd_pcm_hw_param_value_min(slave_params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, NULL));
min_period_size *= oss_frame_size;
min_period_size = roundup_pow_of_two(min_period_size);
if (oss_period_size < min_period_size)
oss_period_size = min_period_size;
if (min_period_size) {
min_period_size *= oss_frame_size;
min_period_size = roundup_pow_of_two(min_period_size);
if (oss_period_size < min_period_size)
oss_period_size = min_period_size;
}
max_period_size = snd_pcm_plug_client_size(substream,
snd_pcm_hw_param_value_max(slave_params, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, NULL));
max_period_size *= oss_frame_size;
max_period_size = rounddown_pow_of_two(max_period_size);
if (oss_period_size > max_period_size)
oss_period_size = max_period_size;
if (max_period_size) {
max_period_size *= oss_frame_size;
max_period_size = rounddown_pow_of_two(max_period_size);
if (oss_period_size > max_period_size)
oss_period_size = max_period_size;
}
oss_periods = oss_buffer_size / oss_period_size;