Re: [syzbot] [wireless?] KMSAN: uninit-value in ath9k_hw_init

[Fedor Pchelkin <pchelkin@ispras.ru>]

#syz test: https://github.com/google/kmsan.git master

--- a/drivers/net/wireless/ath/ath9k/htc_drv_init.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
@@ -259,7 +259,7 @@ static void ath9k_multi_regread(void *hw_priv, u32 *addr,
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *) common->priv;
 	__be32 tmpaddr[8];
-	__be32 tmpval[8];
+	__be32 tmpval[8] = {0};
 	int i, ret;
 
 	for (i = 0; i < count; i++) {
--- a/drivers/net/wireless/ath/ath9k/wmi.c
+++ b/drivers/net/wireless/ath/ath9k/wmi.c
@@ -204,8 +204,13 @@ static void ath9k_wmi_rsp_callback(struct wmi *wmi, struct sk_buff *skb)
 {
 	skb_pull(skb, sizeof(struct wmi_cmd_hdr));
 
+	if (unlikely(skb->len < wmi->cmd_rsp_len))
+		return;
+
 	if (wmi->cmd_rsp_buf != NULL && wmi->cmd_rsp_len != 0)
 		memcpy(wmi->cmd_rsp_buf, skb->data, wmi->cmd_rsp_len);
+	else
+		return;
 
 	complete(&wmi->cmd_wait);
 }
@@ -221,6 +226,9 @@ static void ath9k_wmi_ctrl_rx(void *priv, struct sk_buff *skb,
 	if (unlikely(wmi->stopped))
 		goto free_skb;
 
+	if (unlikely(skb->len < sizeof(struct wmi_cmd_hdr)))
+		goto free_skb;
+
 	hdr = (struct wmi_cmd_hdr *) skb->data;
 	cmd_id = be16_to_cpu(hdr->command_id);
 
@@ -308,8 +316,11 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
 	unsigned long time_left;
 	int ret = 0;
 
-	if (ah->ah_flags & AH_UNPLUGGED)
-		return 0;
+	if (ah->ah_flags & AH_UNPLUGGED) {
+		ath_dbg(common, WMI, "Device unplugged for WMI command: %s\n",
+			wmi_cmd_to_name(cmd_id));
+		return -ENODEV;
+	}
 
 	skb = alloc_skb(headroom + cmd_len, GFP_ATOMIC);
 	if (!skb)
@@ -342,15 +353,22 @@ int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
 		ath_dbg(common, WMI, "Timeout waiting for WMI command: %s\n",
 			wmi_cmd_to_name(cmd_id));
 		wmi->last_seq_id = 0;
+		wmi->cmd_rsp_buf = NULL;
+		wmi->cmd_rsp_len = 0;
 		mutex_unlock(&wmi->op_mutex);
 		return -ETIMEDOUT;
 	}
 
+	wmi->cmd_rsp_buf = NULL;
+	wmi->cmd_rsp_len = 0;
+
 	mutex_unlock(&wmi->op_mutex);
 
 	return 0;
 
 out:
+	wmi->cmd_rsp_buf = NULL;
+	wmi->cmd_rsp_len = 0;
 	ath_dbg(common, WMI, "WMI failure for: %s\n", wmi_cmd_to_name(cmd_id));
 	mutex_unlock(&wmi->op_mutex);
 	kfree_skb(skb);
--