From: Takashi Iwai <tiwai@suse.de>
Date: Tue, 7 Dec 2021 15:33:23 +0000 (+0100)
Subject: ALSA: mixart: Add sanity check for timer notify streams
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=403c521003a1364fd2d7c01a2a1f66ed025fb94a;p=uclinux-h8%2Flinux.git

ALSA: mixart: Add sanity check for timer notify streams

The miXart timer notification is a variable length, and if a hardware
is screwed up, we may access over the actual data size.  Let's add a
sanity check and bail out if an invalid value is received.

Link: https://lore.kernel.org/r/20211207153323.27098-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/pci/mixart/mixart_core.c b/sound/pci/mixart/mixart_core.c
index 853083dd4bad..a047ed0f84e9 100644
--- a/sound/pci/mixart/mixart_core.c
+++ b/sound/pci/mixart/mixart_core.c
@@ -443,6 +443,8 @@ irqreturn_t snd_mixart_threaded_irq(int irq, void *dev_id)
 				notify = (struct mixart_timer_notify *)mixart_msg_data;
 
 				BUILD_BUG_ON(sizeof(notify) > sizeof(mixart_msg_data));
+				if (snd_BUG_ON(notify->stream_count > ARRAY_SIZE(notify->streams)))
+					break;
 				for(i=0; i<notify->stream_count; i++) {
 
 					u32 buffer_id = notify->streams[i].buffer_id;