From: Cezary Rojewski cezary.rojewski@intel.com

mainline inclusion from mainline-v6.7-rc1 commit f93dc90c2e8ed664985e366aa6459ac83cdab236 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RFHM CVE: CVE-2023-52806

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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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 cezary.rojewski@intel.com Link: https://lore.kernel.org/r/20231006102857.749143-2-cezary.rojewski@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Zeng Heng zengheng4@huawei.com --- 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 ce77a5320163..e887c4f3974c 100644 --- a/sound/hda/hdac_stream.c +++ b/sound/hda/hdac_stream.c @@ -293,8 +293,10 @@ 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) {