list_first_entry() never returns NULL — if the list is empty, it still returns a pointer to an invalid object, leading to potential invalid memory access when dereferenced. Fix this by checking list_empty() before calling list_first_entry(), and only copying the MAC address when the list is not empty. Fixes: e3219ce6a775 ("i40e: Add support for client interface for IWARP driver") Signed-off-by: Zhen Ni --- drivers/net/ethernet/intel/i40e/i40e_client.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/i40e/i40e_client.c b/drivers/net/ethernet/intel/i40e/i40e_client.c index 5f1a405cbbf8..0a72157aee0e 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_client.c +++ b/drivers/net/ethernet/intel/i40e/i40e_client.c @@ -359,12 +359,13 @@ static void i40e_client_add_instance(struct i40e_pf *pf) if (i40e_client_get_params(vsi, &cdev->lan_info.params)) goto free_cdev; - mac = list_first_entry(&cdev->lan_info.netdev->dev_addrs.list, - struct netdev_hw_addr, list); - if (mac) + if (!list_empty(&cdev->lan_info.netdev->dev_addrs.list)) { + mac = list_first_entry(&cdev->lan_info.netdev->dev_addrs.list, + struct netdev_hw_addr, list); ether_addr_copy(cdev->lan_info.lanmac, mac->addr); - else + } else { dev_err(&pf->pdev->dev, "MAC address list is empty!\n"); + } pf->cinst = cdev; -- 2.20.1