[SRU][J][PATCH 1/2] net: make sock_inuse_add() available

[Massimiliano Pellizzer]

From: Eric Dumazet <edumazet at google.com>

MPTCP hard codes it, let us instead provide this helper.

Signed-off-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit d477eb9004845cb2dc92ad5eed79a437738a868a)
CVE-2024-53168
Signed-off-by: Massimiliano Pellizzer <massimiliano.pellizzer at canonical.com>
---
 include/net/sock.h  | 10 ++++++++++
 net/core/sock.c     | 10 ----------
 net/mptcp/subflow.c |  4 +---
 3 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index ca3cc2b325d7..0461890f10ae 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1472,6 +1472,12 @@ static inline void sock_prot_inuse_add(const struct net *net,
 {
 	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
 }
+
+static inline void sock_inuse_add(const struct net *net, int val)
+{
+	this_cpu_add(*net->core.sock_inuse, val);
+}
+
 int sock_prot_inuse_get(struct net *net, struct proto *proto);
 int sock_inuse_get(struct net *net);
 #else
@@ -1479,6 +1485,10 @@ static inline void sock_prot_inuse_add(const struct net *net,
 				       const struct proto *prot, int val)
 {
 }
+
+static inline void sock_inuse_add(const struct net *net, int val)
+{
+}
 #endif
 
 
diff --git a/net/core/sock.c b/net/core/sock.c
index dce2bf8dfd1d..7f7f02a01f2d 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -144,8 +144,6 @@
 static DEFINE_MUTEX(proto_list_mutex);
 static LIST_HEAD(proto_list);
 
-static void sock_inuse_add(struct net *net, int val);
-
 /**
  * sk_ns_capable - General socket capability test
  * @sk: Socket to use a capability on or through
@@ -3519,11 +3517,6 @@ int sock_prot_inuse_get(struct net *net, struct proto *prot)
 }
 EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
 
-static void sock_inuse_add(struct net *net, int val)
-{
-	this_cpu_add(*net->core.sock_inuse, val);
-}
-
 int sock_inuse_get(struct net *net)
 {
 	int cpu, res = 0;
@@ -3602,9 +3595,6 @@ static inline void release_proto_idx(struct proto *prot)
 {
 }
 
-static void sock_inuse_add(struct net *net, int val)
-{
-}
 #endif
 
 static void tw_prot_cleanup(struct timewait_sock_ops *twsk_prot)
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index d8b33e10750b..919a13c73448 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1579,9 +1579,7 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock)
 	 */
 	sf->sk->sk_net_refcnt = 1;
 	get_net(net);
-#ifdef CONFIG_PROC_FS
-	this_cpu_add(*net->core.sock_inuse, 1);
-#endif
+	sock_inuse_add(net, 1);
 	err = tcp_set_ulp(sf->sk, "mptcp");
 	release_sock(sf->sk);
 
-- 
2.43.0