[PATCH 4.9 001/240] net: usb: ax88179_178a: initialize local variables before use

Greg Kroah-Hartman
2021-05-20T11:01:56Z

From: Phillip Potter <phil@philpotter.co.uk>

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>
---
drivers/net/usb/ax88179_178a.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -307,12 +307,12 @@ static int ax88179_read_cmd(struct usbne
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;