1 files changed, 12 insertions, 32 deletions

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 56263c2c4014..7b3794459783 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1135,36 +1135,12 @@ next:
 	return 0;
 }
 
-struct addr_entry_release_work {
-	struct rcu_work	rwork;
-	struct mptcp_pm_addr_entry *entry;
-};
-
-static void mptcp_pm_release_addr_entry(struct work_struct *work)
+/* caller must ensure the RCU grace period is already elapsed */
+static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
 {
-	struct addr_entry_release_work *w;
-	struct mptcp_pm_addr_entry *entry;
-
-	w = container_of(to_rcu_work(work), struct addr_entry_release_work, rwork);
-	entry = w->entry;
-	if (entry) {
-		if (entry->lsk)
-			sock_release(entry->lsk);
-		kfree(entry);
-	}
-	kfree(w);
-}
-
-static void mptcp_pm_free_addr_entry(struct mptcp_pm_addr_entry *entry)
-{
-	struct addr_entry_release_work *w;
-
-	w = kmalloc(sizeof(*w), GFP_ATOMIC);
-	if (w) {
-		INIT_RCU_WORK(&w->rwork, mptcp_pm_release_addr_entry);
-		w->entry = entry;
-		queue_rcu_work(system_wq, &w->rwork);
-	}
+	if (entry->lsk)
+		sock_release(entry->lsk);
+	kfree(entry);
 }
 
 static int mptcp_nl_remove_id_zero_address(struct net *net,
@@ -1244,7 +1220,8 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 	spin_unlock_bh(&pernet->lock);
 
 	mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
-	mptcp_pm_free_addr_entry(entry);
+	synchronize_rcu();
+	__mptcp_pm_release_addr_entry(entry);
 
 	return ret;
 }
@@ -1297,6 +1274,7 @@ static void mptcp_nl_remove_addrs_list(struct net *net,
 	}
 }
 
+/* caller must ensure the RCU grace period is already elapsed */
 static void __flush_addrs(struct list_head *list)
 {
 	while (!list_empty(list)) {
@@ -1305,7 +1283,7 @@ static void __flush_addrs(struct list_head *list)
 		cur = list_entry(list->next,
 				 struct mptcp_pm_addr_entry, list);
 		list_del_rcu(&cur->list);
-		mptcp_pm_free_addr_entry(cur);
+		__mptcp_pm_release_addr_entry(cur);
 	}
 }
 
@@ -1329,6 +1307,7 @@ static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
 	bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
 	spin_unlock_bh(&pernet->lock);
 	mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
+	synchronize_rcu();
 	__flush_addrs(&free_list);
 	return 0;
 }
@@ -1939,7 +1918,8 @@ static void __net_exit pm_nl_exit_net(struct list_head *net_list)
 		struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
 
 		/* net is removed from namespace list, can't race with
-		 * other modifiers
+		 * other modifiers, also netns core already waited for a
+		 * RCU grace period.
 		 */
 		__flush_addrs(&pernet->local_addr_list);
 	}