Set the practical limit to the period size (the fragment shift in OSS) instead of a full 31bit; a too large value could lead to the exhaust of memory as we allocate temporary buffers of the period size, too. As of this patch, we set to 16MB limit, which should cover all use cases. Reported-by: syzbot+bb348e9f9a954d42746f@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-by: Bixuan Cui <cuibixuan@xxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/1638270978-42412-1-git-send-email-cuibixuan@xxxxxxxxxxxxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> --- sound/core/oss/pcm_oss.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index bec7590bc84b..89c4910daf02 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -1962,7 +1962,7 @@ static int snd_pcm_oss_set_fragment1(struct snd_pcm_substream *substream, unsign if (runtime->oss.subdivision || runtime->oss.fragshift) return -EINVAL; fragshift = val & 0xffff; - if (fragshift >= 31) + if (fragshift >= 25) /* should be large enough */ return -EINVAL; runtime->oss.fragshift = fragshift; runtime->oss.maxfrags = (val >> 16) & 0xffff; -- 2.31.1
