[PATCH AUTOSEL 5.4 17/43] net: usb: Fix uninit-was-stored issue in asix_read_phy_addr()

Sasha Levin
2020-09-07T16:58:39Z

From: Himadri Pandya <himadrispandya@gmail.com>

[ Upstream commit a092b7233f0e000cc6f2c71a49e2ecc6f917a5fc ]

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@syzkaller.appspotmail.com
Signed-off-by: Himadri Pandya <himadrispandya@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 e39f41efda3ec..7bc6e8f856fe0 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;
}
--
2.25.1