This is a note to let you know that I've just added the patch titled
ALSA: hda: prevent undefined shift in snd_hdac_ext_bus_get_link()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-hda-prevent-undefined-shift-in-snd_hdac_ext_bus.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 8d908395c4e841f09230599e2946d9e5ab668c19
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Tue Nov 3 13:18:07 2020 +0300
ALSA: hda: prevent undefined shift in snd_hdac_ext_bus_get_link()
[ Upstream commit 158e1886b6262c1d1c96a18c85fac5219b8bf804 ]
This is harmless, but the "addr" comes from the user and it could lead
to a negative shift or to shift wrapping if it's too high.
Fixes: 0b00a5615dc4 ("ALSA: hdac_ext: add hdac extended controller")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20201103101807.GC1127762@mwanda
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/hda/ext/hdac_ext_controller.c b/sound/hda/ext/hdac_ext_controller.c
index 09ff209df4a30..c87187f635733 100644
--- a/sound/hda/ext/hdac_ext_controller.c
+++ b/sound/hda/ext/hdac_ext_controller.c
@@ -148,6 +148,8 @@ struct hdac_ext_link *snd_hdac_ext_bus_get_link(struct hdac_bus *bus,
return NULL;
if (bus->idx != bus_idx)
return NULL;
+ if (addr < 0 || addr > 31)
+ return NULL;
list_for_each_entry(hlink, &bus->hlink_list, list) {
for (i = 0; i < HDA_MAX_CODECS; i++) {
