The ASIX driver reads the PHY address from the USB device via asix_read_phy_addr(). A malicious or faulty device can return an invalid address (>= PHY_MAX_ADDR), which causes a warning in mdiobus_get_phy(): addr 207 out of range WARNING: drivers/net/phy/mdio_bus.c:76 Validate the PHY address before returning it from asix_read_phy_addr(). Reported-by: syzbot+3d43c9066a5b54902232@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=3d43c9066a5b54902232 Tested-by: syzbot+3d43c9066a5b54902232@syzkaller.appspotmail.com Fixes: 7e88b11a862a ("net: usb: asix: refactor asix_read_phy_addr() and handle errors on return") Signed-off-by: Deepanshu Kartikey --- drivers/net/usb/asix_common.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/usb/asix_common.c b/drivers/net/usb/asix_common.c index 7fd763917ae2..6ab3486072cb 100644 --- a/drivers/net/usb/asix_common.c +++ b/drivers/net/usb/asix_common.c @@ -335,6 +335,11 @@ int asix_read_phy_addr(struct usbnet *dev, bool internal) offset = (internal ? 1 : 0); ret = buf[offset]; + if (ret >= PHY_MAX_ADDR) { + netdev_err(dev->net, "invalid PHY address: %d\n", ret); + return -ENODEV; + } + netdev_dbg(dev->net, "%s PHY address 0x%x\n", internal ? "internal" : "external", ret); -- 2.43.0