mptcp: deduplicate error paths on endpoint creation

[ Upstream commit 976d302fb6165ad620778d7ba834cde6e3fe9f9f ]

When endpoint creation fails, we need to free the newly allocated
entry and eventually destroy the paired mptcp listener socket.

Consolidate such action in a single point let all the errors path
reach it.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: ad2171009d96 ("mptcp: fix locking for in-kernel listener creation")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 9813ed0..fdf2ee2 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1003,16 +1003,12 @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
                return err;
 
        msk = mptcp_sk(entry->lsk->sk);
-       if (!msk) {
-               err = -EINVAL;
-               goto out;
-       }
+       if (!msk)
+               return -EINVAL;
 
        ssock = __mptcp_nmpc_socket(msk);
-       if (!ssock) {
-               err = -EINVAL;
-               goto out;
-       }
+       if (!ssock)
+               return -EINVAL;
 
        mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
@@ -1022,20 +1018,16 @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
        err = kernel_bind(ssock, (struct sockaddr *)&addr, addrlen);
        if (err) {
                pr_warn("kernel_bind error, err=%d", err);
-               goto out;
+               return err;
        }
 
        err = kernel_listen(ssock, backlog);
        if (err) {
                pr_warn("kernel_listen error, err=%d", err);
-               goto out;
+               return err;
        }
 
        return 0;
-
-out:
-       sock_release(entry->lsk);
-       return err;
 }
 
 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
@@ -1327,7 +1319,7 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
                return -EINVAL;
        }
 
-       entry = kmalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
+       entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
        if (!entry) {
                GENL_SET_ERR_MSG(info, "can't allocate addr");
                return -ENOMEM;
@@ -1338,22 +1330,21 @@ static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
                ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
                if (ret) {
                        GENL_SET_ERR_MSG(info, "create listen socket error");
-                       kfree(entry);
-                       return ret;
+                       goto out_free;
                }
        }
        ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
        if (ret < 0) {
                GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
-               if (entry->lsk)
-                       sock_release(entry->lsk);
-               kfree(entry);
-               return ret;
+               goto out_free;
        }
 
        mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
-
        return 0;
+
+out_free:
+       __mptcp_pm_release_addr_entry(entry);
+       return ret;
 }
 
 int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,