[PATCH] net: usb: Fix uninit-was-stored issue in asix_read_phy_addr()

From: Himadri Pandya
Date: Thu Aug 27 2020 - 02:54:38 EST


The buffer size is 2 Bytes and we expect to receive the same amount of
data. But sometimes we receive less data and run into uninit-was-stored
issue upon read. Hence modify the error check on the return value to match
with the buffer size as a prevention.

Reported-and-tested by: syzbot+a7e220df5a81d1ab400e@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Himadri Pandya <himadrispandya@xxxxxxxxx>
---
drivers/net/usb/asix_common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c
index e39f41efda3e..7bc6e8f856fe 100644
--- a/drivers/net/usb/asix_common.c
+++ b/drivers/net/usb/asix_common.c
@@ -296,7 +296,7 @@ int asix_read_phy_addr(struct usbnet *dev, int internal)

netdev_dbg(dev->net, "asix_get_phy_addr()\n");

- if (ret < 0) {
+ if (ret < 2) {
netdev_err(dev->net, "Error reading PHYID register: %02x\n", ret);
goto out;
}
--
2.17.1