From 158e1886b6262c1d1c96a18c85fac5219b8bf804 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 3 Nov 2020 13:18:07 +0300 Subject: [PATCH] ALSA: hda: prevent undefined shift in snd_hdac_ext_bus_get_link() 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 Link: https://lore.kernel.org/r/20201103101807.GC1127762@mwanda Signed-off-by: Takashi Iwai --- 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++) {