From 5d78e1c2b7f4be00bbe62141603a631dc7812f35 Mon Sep 17 00:00:00 2001
From: Hillf Danton <hdanton@sina.com>
Date: Tue, 30 Jul 2019 17:24:36 +0800
Subject: [PATCH] ALSA: usb-audio: Fix gpf in snd_usb_pipe_sanity_check
Git-commit: 5d78e1c2b7f4be00bbe62141603a631dc7812f35
Patch-mainline: 5.3-rc3
References: bsc#1051510,CVE-2019-15222,bsc#1146531
syzbot found the following crash on:
general protection fault: 0000 [#1] SMP KASAN
RIP: 0010:snd_usb_pipe_sanity_check+0x80/0x130 sound/usb/helper.c:75
Call Trace:
snd_usb_motu_microbookii_communicate.constprop.0+0xa0/0x2fb sound/usb/quirks.c:1007
snd_usb_motu_microbookii_boot_quirk sound/usb/quirks.c:1051 [inline]
snd_usb_apply_boot_quirk.cold+0x163/0x370 sound/usb/quirks.c:1280
usb_audio_probe+0x2ec/0x2010 sound/usb/card.c:576
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x650 drivers/base/dd.c:548
....
It was introduced in commit 801ebf1043ae for checking pipe and endpoint
types. It is fixed by adding a check of the ep pointer in question.
Buglink: https://syzkaller.appspot.com/bug?extid=d59c4387bfb6eced94e2
Reported-by: syzbot <syzbot+d59c4387bfb6eced94e2@syzkaller.appspotmail.com>
Fixes: 801ebf1043ae ("ALSA: usb-audio: Sanity checks for each pipe and EP types")
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/usb/helper.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/usb/helper.c b/sound/usb/helper.c
index 71d5f540334a..4c12cc5b53fd 100644
--- a/sound/usb/helper.c
+++ b/sound/usb/helper.c
@@ -72,7 +72,7 @@ int snd_usb_pipe_sanity_check(struct usb_device *dev, unsigned int pipe)
struct usb_host_endpoint *ep;
ep = usb_pipe_endpoint(dev, pipe);
- if (usb_pipetype(pipe) != pipetypes[usb_endpoint_type(&ep->desc)])
+ if (!ep || usb_pipetype(pipe) != pipetypes[usb_endpoint_type(&ep->desc)])
return -EINVAL;
return 0;
}
--
2.16.4