Patch "af_key: Add lock to key dump" has been added to the 4.9-stable tree

@@ -63,6 +63,7 @@ struct pfkey_sock {
 		} u;
 		struct sk_buff	*skb;
 	} dump;
+	struct mutex dump_lock;
 };
 
 static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,

@@ -143,6 +144,7 @@ static int pfkey_create(struct net *net,
 {
 	struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
 	struct sock *sk;
+	struct pfkey_sock *pfk;
 	int err;
 
 	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))

@@ -157,6 +159,9 @@ static int pfkey_create(struct net *net,
 	if (sk == NULL)
 		goto out;
 
+	pfk = pfkey_sk(sk);
+	mutex_init(&pfk->dump_lock);
+
 	sock->ops = &pfkey_ops;
 	sock_init_data(sock, sk);
 

@@ -285,13 +290,23 @@ static int pfkey_do_dump(struct pfkey_so
 	struct sadb_msg *hdr;
 	int rc;
 
+	mutex_lock(&pfk->dump_lock);
+	if (!pfk->dump.dump) {
+		rc = 0;
+		goto out;
+	}
+
 	rc = pfk->dump.dump(pfk);
-	if (rc == -ENOBUFS)
-		return 0;
+	if (rc == -ENOBUFS) {
+		rc = 0;
+		goto out;
+	}
 
 	if (pfk->dump.skb) {
-		if (!pfkey_can_dump(&pfk->sk))
-			return 0;
+		if (!pfkey_can_dump(&pfk->sk)) {
+			rc = 0;
+			goto out;
+		}
 
 		hdr = (struct sadb_msg *) pfk->dump.skb->data;
 		hdr->sadb_msg_seq = 0;

@@ -302,6 +317,9 @@ static int pfkey_do_dump(struct pfkey_so
 	}
 
 	pfkey_terminate_dump(pfk);
+
+out:
+	mutex_unlock(&pfk->dump_lock);
 	return rc;
 }
 

@@ -1806,19 +1824,26 @@ static int pfkey_dump(struct sock *sk, s
 	struct xfrm_address_filter *filter = NULL;
 	struct pfkey_sock *pfk = pfkey_sk(sk);
 
-	if (pfk->dump.dump != NULL)
+	mutex_lock(&pfk->dump_lock);
+	if (pfk->dump.dump != NULL) {
+		mutex_unlock(&pfk->dump_lock);
 		return -EBUSY;
+	}
 
 	proto = pfkey_satype2proto(hdr->sadb_msg_satype);
-	if (proto == 0)
+	if (proto == 0) {
+		mutex_unlock(&pfk->dump_lock);
 		return -EINVAL;
+	}
 
 	if (ext_hdrs[SADB_X_EXT_FILTER - 1]) {
 		struct sadb_x_filter *xfilter = ext_hdrs[SADB_X_EXT_FILTER - 1];
 
 		filter = kmalloc(sizeof(*filter), GFP_KERNEL);
-		if (filter == NULL)
+		if (filter == NULL) {
+			mutex_unlock(&pfk->dump_lock);
 			return -ENOMEM;
+		}
 
 		memcpy(&filter->saddr, &xfilter->sadb_x_filter_saddr,
 		       sizeof(xfrm_address_t));

@@ -1834,6 +1859,7 @@ static int pfkey_dump(struct sock *sk, s
 	pfk->dump.dump = pfkey_dump_sa;
 	pfk->dump.done = pfkey_dump_sa_done;
 	xfrm_state_walk_init(&pfk->dump.u.state, proto, filter);
+	mutex_unlock(&pfk->dump_lock);
 
 	return pfkey_do_dump(pfk);
 }

@@ -2693,14 +2719,18 @@ static int pfkey_spddump(struct sock *sk
 {
 	struct pfkey_sock *pfk = pfkey_sk(sk);
 
-	if (pfk->dump.dump != NULL)
+	mutex_lock(&pfk->dump_lock);
+	if (pfk->dump.dump != NULL) {
+		mutex_unlock(&pfk->dump_lock);
 		return -EBUSY;
+	}
 
 	pfk->dump.msg_version = hdr->sadb_msg_version;
 	pfk->dump.msg_portid = hdr->sadb_msg_pid;
 	pfk->dump.dump = pfkey_dump_sp;
 	pfk->dump.done = pfkey_dump_sp_done;
 	xfrm_policy_walk_init(&pfk->dump.u.policy, XFRM_POLICY_TYPE_MAIN);
+	mutex_unlock(&pfk->dump_lock);
 
 	return pfkey_do_dump(pfk);
 }