Commit a68229ca authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller
Browse files

nixge: fix mac address error handling again 



The change to eth_hw_addr_set() caused gcc to correctly spot a
bug that was introduced in an earlier incorrect fix:

In file included from include/linux/etherdevice.h:21,
                 from drivers/net/ethernet/ni/nixge.c:7:
In function '__dev_addr_set',
    inlined from 'eth_hw_addr_set' at include/linux/etherdevice.h:319:2,
    inlined from 'nixge_probe' at drivers/net/ethernet/ni/nixge.c:1286:3:
include/linux/netdevice.h:4648:9: error: 'memcpy' reading 6 bytes from a region of size 0 [-Werror=stringop-overread]
 4648 |         memcpy(dev->dev_addr, addr, len);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As nixge_get_nvmem_address() can return either NULL or an error
pointer, the NULL check is wrong, and we can end up reading from
ERR_PTR(-EOPNOTSUPP), which gcc knows to contain zero readable
bytes.

Make the function always return an error pointer again but fix
the check to match that.

Fixes: f3956ebb ("ethernet: use eth_hw_addr_set() instead of ether_addr_copy()")
Fixes: abcd3d6f ("net: nixge: Fix error path for obtaining mac address")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7a61432d

drivers/net/ethernet/ni/nixge.c

+2 −2
Original line number Diff line number Diff line
@@ -1209,7 +1209,7 @@ static void *nixge_get_nvmem_address(struct device *dev) 


	cell = nvmem_cell_get(dev, "address");

	if (IS_ERR(cell))

		return NULL;

		return cell;



	mac = nvmem_cell_read(cell, &cell_size);

	nvmem_cell_put(cell);
@@ -1282,7 +1282,7 @@ static int nixge_probe(struct platform_device *pdev) 
	ndev->max_mtu = NIXGE_JUMBO_MTU;



	mac_addr = nixge_get_nvmem_address(&pdev->dev);

	if (mac_addr && is_valid_ether_addr(mac_addr)) {

	if (!IS_ERR(mac_addr) && is_valid_ether_addr(mac_addr)) {

		eth_hw_addr_set(ndev, mac_addr);

		kfree(mac_addr);

	} else {