From 158e1886b6262c1d1c96a18c85fac5219b8bf804 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 3 Nov 2020 13:18:07 +0300
Subject: [PATCH] ALSA: hda: prevent undefined shift in snd_hdac_ext_bus_get_link()
Git-commit: 158e1886b6262c1d1c96a18c85fac5219b8bf804
Patch-mainline: v5.10-rc3
References: git-fixes
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@oracle.com>
Link: https://lore.kernel.org/r/20201103101807.GC1127762@mwanda
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/hda/ext/hdac_ext_controller.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/hda/ext/hdac_ext_controller.c b/sound/hda/ext/hdac_ext_controller.c
index 4d060d5b1db6..b0c0ef824d7d 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++) {
--
2.16.4