On Sun, 2020-10-11 at 10:59 -0700, Jakub Kicinski wrote: > On Sun, 11 Oct 2020 23:00:30 +0530 Anant Thazhemadam wrote: > > In set_ethernet_addr(), if get_registers() succeeds, the ethernet address > > that was read must be copied over. Otherwise, a random ethernet address > > must be assigned. > > > > get_registers() returns 0 if successful, and negative error number > > otherwise. However, in set_ethernet_addr(), this return value is > > incorrectly checked. > > > > Since this return value will never be equal to sizeof(node_id), a > > random MAC address will always be generated and assigned to the > > device; even in cases when get_registers() is successful. > > > > Correctly modifying the condition that checks if get_registers() was > > successful or not fixes this problem, and copies the ethernet address > > appropriately. There are many unchecked uses of set_registers and get_registers in this file. If failures are really expected, then it might be better to fix them up too. $ git grep -w '[gs]et_registers' drivers/net/usb/rtl8150.c drivers/net/usb/rtl8150.c:static int get_registers(rtl8150_t * dev, u16 indx, u16 size, void *data) drivers/net/usb/rtl8150.c:static int set_registers(rtl8150_t * dev, u16 indx, u16 size, const void *data) drivers/net/usb/rtl8150.c: set_registers(dev, PHYADD, sizeof(data), data); drivers/net/usb/rtl8150.c: set_registers(dev, PHYCNT, 1, &tmp); drivers/net/usb/rtl8150.c: get_registers(dev, PHYCNT, 1, data); drivers/net/usb/rtl8150.c: get_registers(dev, PHYDAT, 2, data); drivers/net/usb/rtl8150.c: set_registers(dev, PHYADD, sizeof(data), data); drivers/net/usb/rtl8150.c: set_registers(dev, PHYCNT, 1, &tmp); drivers/net/usb/rtl8150.c: get_registers(dev, PHYCNT, 1, data); drivers/net/usb/rtl8150.c: ret = get_registers(dev, IDR, sizeof(node_id), node_id); drivers/net/usb/rtl8150.c: set_registers(dev, IDR, netdev->addr_len, netdev->dev_addr); drivers/net/usb/rtl8150.c: get_registers(dev, CR, 1, &cr); drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); drivers/net/usb/rtl8150.c: set_registers(dev, IDR_EEPROM + (i * 2), 2, drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &data); drivers/net/usb/rtl8150.c: get_registers(dev, CR, 1, &data); drivers/net/usb/rtl8150.c: set_registers(dev, RCR, 1, &rcr); drivers/net/usb/rtl8150.c: set_registers(dev, TCR, 1, &tcr); drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); drivers/net/usb/rtl8150.c: get_registers(dev, MSR, 1, &msr); drivers/net/usb/rtl8150.c: get_registers(dev, CR, 1, &cr); drivers/net/usb/rtl8150.c: set_registers(dev, CR, 1, &cr); drivers/net/usb/rtl8150.c: get_registers(dev, CSCR, 2, &tmp); drivers/net/usb/rtl8150.c: set_registers(dev, IDR, 6, netdev->dev_addr); drivers/net/usb/rtl8150.c: get_registers(dev, BMCR, 2, &bmcr); drivers/net/usb/rtl8150.c: get_registers(dev, ANLP, 2, &lpa);
