In some cases, the appl_ptr passed by userspace is not checked before being used. This patch adds an unconditional check and returns an error code should the appl_ptr exceed the ALSA 'boundary'. Suggested-by: Takashi Iwai <tiwai@xxxxxxx> Reviewed-by: Takashi Iwai <tiwai@xxxxxxx> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx> Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx> --- sound/core/pcm_lib.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 4f4b4739f987..fdd992772b20 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -2133,6 +2133,9 @@ int pcm_lib_apply_appl_ptr(struct snd_pcm_substream *substream, if (old_appl_ptr == appl_ptr) return 0; + if (appl_ptr >= runtime->boundary) + return -EINVAL; + runtime->control->appl_ptr = appl_ptr; if (substream->ops->ack) { ret = substream->ops->ack(substream); -- 2.25.1