From: Cezary Rojewski Date: Fri, 6 Oct 2023 10:28:55 +0000 (+0200) Subject: ALSA: hda: Fix possible null-ptr-deref when assigning a stream X-Git-Tag: v4.14.331~36 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7de25112de8222fd20564769e6c99dc9f9738a0b;p=thirdparty%2Fkernel%2Fstable.git ALSA: hda: Fix possible null-ptr-deref when assigning a stream [ Upstream commit f93dc90c2e8ed664985e366aa6459ac83cdab236 ] While AudioDSP drivers assign streams exclusively of HOST or LINK type, nothing blocks a user to attempt to assign a COUPLED stream. As supplied substream instance may be a stub, what is the case when code-loading, such scenario ends with null-ptr-deref. Signed-off-by: Cezary Rojewski Link: https://lore.kernel.org/r/20231006102857.749143-2-cezary.rojewski@intel.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c index e1472c7ab6c17..609dc5133fba9 100644 --- a/sound/hda/hdac_stream.c +++ b/sound/hda/hdac_stream.c @@ -241,8 +241,10 @@ struct hdac_stream *snd_hdac_stream_assign(struct hdac_bus *bus, struct hdac_stream *res = NULL; /* make a non-zero unique key for the substream */ - int key = (substream->pcm->device << 16) | (substream->number << 2) | - (substream->stream + 1); + int key = (substream->number << 2) | (substream->stream + 1); + + if (substream->pcm) + key |= (substream->pcm->device << 16); list_for_each_entry(azx_dev, &bus->stream_list, list) { if (azx_dev->direction != substream->stream)