[PATCH AUTOSEL 4.4 6/6] net: usb: rtl8150: set random MAC address when set_ethernet_addr() fails
From: Sasha Levin <sashal@kernel.org>
Date: 2020-10-12 19:04:54
Also in:
lkml, netdev, stable
Subsystem:
networking drivers, the rest, usb networking drivers, usb rtl8150 driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Petko Manolov
From: Anant Thazhemadam <redacted> [ Upstream commit f45a4248ea4cc13ed50618ff066849f9587226b2 ] 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 <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/usb/rtl8150.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
index 58b1e18fdd64d..7230f1e8210ff 100644
--- a/drivers/net/usb/rtl8150.c
+++ b/drivers/net/usb/rtl8150.c@@ -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)
--
2.25.1