This is a note to let you know that I've just added the patch titled nixge: fix mac address error handling again to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nixge-fix-mac-address-error-handling-again.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a68229ca634066975fff6d4780155bd2eb14a82a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd@xxxxxxxx> Date: Mon, 22 Nov 2021 16:02:49 +0100 Subject: nixge: fix mac address error handling again From: Arnd Bergmann <arnd@xxxxxxxx> commit a68229ca634066975fff6d4780155bd2eb14a82a upstream. 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: f3956ebb3bf0 ("ethernet: use eth_hw_addr_set() instead of ether_addr_copy()") Fixes: abcd3d6fc640 ("net: nixge: Fix error path for obtaining mac address") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/ni/nixge.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/ni/nixge.c +++ b/drivers/net/ethernet/ni/nixge.c @@ -1211,7 +1211,7 @@ static void *nixge_get_nvmem_address(str 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); @@ -1284,7 +1284,7 @@ static int nixge_probe(struct platform_d 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 { Patches currently in stable-queue which might be from arnd@xxxxxxxx are queue-5.15/nixge-fix-mac-address-error-handling-again.patch