From: Phillip Potter <phil@philpotter.co.uk>
Date: Thu, 1 Apr 2021 22:36:07 +0000 (+0100)
Subject: net: usb: ax88179_178a: initialize local variables before use
X-Git-Tag: v4.4.269~185
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7891aeb6f188f0887eb3e6c34e8cc68239f8e20c;p=thirdparty%2Fkernel%2Fstable.git

net: usb: ax88179_178a: initialize local variables before use

commit bd78980be1a68d14524c51c4b4170782fada622b upstream.

Use memset to initialize local array in drivers/net/usb/ax88179_178a.c, and
also set a local u16 and u32 variable to 0. Fixes a KMSAN found uninit-value bug
reported by syzbot at:
https://syzkaller.appspot.com/bug?id=00371c73c72f72487c1d0bfe0cc9d00de339d5aa

Reported-by: syzbot+4993e4a0e237f1b53747@syzkaller.appspotmail.com
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 2dcc8a039d42e..53cef8cd1aad7 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -307,12 +307,12 @@ static int ax88179_read_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
 	int ret;
 
 	if (2 == size) {
-		u16 buf;
+		u16 buf = 0;
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, &buf, 0);
 		le16_to_cpus(&buf);
 		*((u16 *)data) = buf;
 	} else if (4 == size) {
-		u32 buf;
+		u32 buf = 0;
 		ret = __ax88179_read_cmd(dev, cmd, value, index, size, &buf, 0);
 		le32_to_cpus(&buf);
 		*((u32 *)data) = buf;