From f93dc90c2e8ed664985e366aa6459ac83cdab236 Mon Sep 17 00:00:00 2001 From: Cezary Rojewski Date: Fri, 6 Oct 2023 12:28:55 +0200 Subject: [PATCH] ALSA: hda: Fix possible null-ptr-deref when assigning a stream 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 --- sound/hda/hdac_stream.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c index 5382894bebab..a132108fba40 100644 --- a/sound/hda/hdac_stream.c +++ b/sound/hda/hdac_stream.c @@ -362,8 +362,10 @@ 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); spin_lock_irq(&bus->reg_lock); list_for_each_entry(azx_dev, &bus->stream_list, list) {