From: Jaroslav Kysela Date: Tue, 13 Oct 2020 17:28:29 +0000 (+0200) Subject: pcm: meter / s16 - add protection for the maximum copied frames X-Git-Tag: v1.2.4~9 X-Git-Url: https://git.alsa-project.org/?a=commitdiff_plain;h=a6c8ac0c85ca1b16684a687c7000c73aa38b7776;p=alsa-lib.git pcm: meter / s16 - add protection for the maximum copied frames The rewind or forward may cause the stream pointer change. Although this patch does not fix the real meter update issue, it breaks the possible big loops when the stream pointers are desynced with the meters. It does not make sense to copy more samples than the pcm buffer contains. Link: https://lore.kernel.org/alsa-devel/f56d6a67-014a-e562-c253-830c0ec03717@ivitera.com/ Signed-off-by: Jaroslav Kysela --- diff --git a/src/pcm/pcm_meter.c b/src/pcm/pcm_meter.c index 20b41876..2dcf8e45 100644 --- a/src/pcm/pcm_meter.c +++ b/src/pcm/pcm_meter.c @@ -79,6 +79,8 @@ static void snd_pcm_meter_add_frames(snd_pcm_t *pcm, snd_pcm_uframes_t frames) { snd_pcm_meter_t *meter = pcm->private_data; + if (frames > pcm->buffer_size) + frames = pcm->buffer_size; while (frames > 0) { snd_pcm_uframes_t n = frames; snd_pcm_uframes_t dst_offset = ptr % meter->buf_size; @@ -1100,6 +1102,8 @@ static void s16_update(snd_pcm_scope_t *scope) size = meter->now - s16->old; if (size < 0) size += spcm->boundary; + if (size > (snd_pcm_sframes_t)s16->pcm->buffer_size) + size = s16->pcm->buffer_size; offset = s16->old % meter->buf_size; while (size > 0) { snd_pcm_uframes_t frames = size;