Re: [PATCH AUTOSEL 5.8 18/24] net: usb: rtl8150: set random MAC address when set_ethernet_addr() fails
From: Joe Perches <joe@perches.com>
Date: 2020-10-12 19:11:24
Also in:
linux-usb, lkml, stable
On Mon, 2020-10-12 at 15:02 -0400, Sasha Levin wrote:
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.
This autosel is premature. This patch always sets a random MAC. See the follow on patch: https://lkml.org/lkml/2020/10/11/131 To my knowledge, this follow-ob has yet to be applied:
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
[]
quoted hunk ↗ jump to hunk
@@ -274,12 +274,20 @@ 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)) {
So this needs to use
if (!ret) {
or
if (ret < 0)
and reversed code blocks
+ 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)