[PATCH 5.11 03/31] net: usb: ax88179_178a: initialize local variables before use

From: Greg Kroah-Hartman
Date: Wed May 05 2021 - 08:11:57 EST


From: Phillip Potter <phil@xxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Phillip Potter <phil@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/usb/ax88179_178a.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -296,12 +296,12 @@ 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;
@@ -1296,6 +1296,8 @@ static void ax88179_get_mac_addr(struct
{
u8 mac[ETH_ALEN];

+ memset(mac, 0, sizeof(mac));
+
/* Maybe the boot loader passed the MAC address via device tree */
if (!eth_platform_get_mac_address(&dev->udev->dev, mac)) {
netif_dbg(dev, ifup, dev->net,