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(+)

--- a/sound/hda/ext/hdac_ext_controller.c

+++ b/sound/hda/ext/hdac_ext_controller.c

@@ -155,6 +155,8 @@ struct hdac_ext_link *snd_hdac_ext_bus_g

 		return NULL;

 	if (ebus->idx != bus_idx)

 		return NULL;

+	if (addr < 0 || addr > 31)

+		return NULL;

 	list_for_each_entry(hlink, &ebus->hlink_list, list) {

 		for (i = 0; i < HDA_MAX_CODECS; i++) {