Hello Sergey Matyukevich, The patch c6ed298ffe09: "qtnfmac: cleanup and unify command error handling" from Oct 5, 2018, leads to the following static checker warning: drivers/net/wireless/quantenna/qtnfmac/commands.c:132 qtnf_cmd_send_with_reply() warn: variable dereferenced before check 'resp' (see line 117) drivers/net/wireless/quantenna/qtnfmac/commands.c 112 ret = qtnf_trans_send_cmd_with_resp(bus, cmd_skb, &resp_skb); 113 if (ret) 114 goto out; 115 116 resp = (const struct qlink_resp *)resp_skb->data; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 117 ret = qtnf_cmd_check_reply_header(resp, cmd_id, mac_id, vif_id, ^^^^ Dereference 118 const_resp_size); 119 if (ret) 120 goto out; 121 122 /* Return length of variable part of response */ 123 if (response_skb && var_resp_size) 124 *var_resp_size = le16_to_cpu(resp->mhdr.len) - const_resp_size; 125 126 out: 127 if (response_skb) 128 *response_skb = resp_skb; 129 else 130 consume_skb(resp_skb); 131 132 if (!ret && resp) ^^^^ This new check is not required. 133 return qtnf_cmd_resp_result_decode(le16_to_cpu(resp->result)); 134 135 pr_warn("VIF%u.%u: cmd 0x%.4X failed: %d\n", 136 mac_id, vif_id, le16_to_cpu(cmd->cmd_id), ret); 137 138 return ret; 139 } regards, dan carpenter