Commit d71f3fb9 authored Oct 05, 2020 by Anant Thazhemadam Committed by Greg Kroah-Hartman Oct 14, 2020

net: usb: rtl8150: set random MAC address when set_ethernet_addr() fails



commit f45a4248ea4cc13ed50618ff066849f9587226b2 upstream.

When get_registers() fails in set_ethernet_addr(),the uninitialized
value of node_id gets copied over as the address.
So, check the return value of get_registers().

If get_registers() executed successfully (i.e., it returns
sizeof(node_id)), copy over the MAC address using ether_addr_copy()
(instead of using memcpy()).

Else, if get_registers() failed instead, a randomly generated MAC
address is set as the MAC address instead.

Reported-by:  <syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com>
Tested-by:  <syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com>
Acked-by: Petko Manolov <petkan@nucleusys.com>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 94c51675

drivers/net/usb/rtl8150.c

+12 −4

Original line number	Diff line number	Diff line
		@@ -277,12 +277,20 @@ static int write_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 reg)
		return 1;
		}

		static inline void set_ethernet_addr(rtl8150_t * dev)
		static void set_ethernet_addr(rtl8150_t *dev)
		{
		u8 node_id[6];
		u8 node_id[ETH_ALEN];
		int ret;

		ret = get_registers(dev, IDR, sizeof(node_id), node_id);

		get_registers(dev, IDR, sizeof(node_id), node_id);
		memcpy(dev->netdev->dev_addr, node_id, sizeof(node_id));
		if (ret == sizeof(node_id)) {
		ether_addr_copy(dev->netdev->dev_addr, node_id);
		} else {
		eth_hw_addr_random(dev->netdev);
		netdev_notice(dev->netdev, "Assigned a random MAC address: %pM\n",
		dev->netdev->dev_addr);
		}
		}

		static int rtl8150_set_mac_address(struct net_device netdev, void p)