[PATCH 5.15 120/279] sock: fix /proc/net/sockstat underflow in sk_clone_lock()

Greg Kroah-Hartman
2021-11-24T13:53:04Z

From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>

[ Upstream commit 938cca9e4109b30ee1d476904538225a825e54eb ]

sk_clone_lock() needs to call sock_inuse_add(1) before entering the
sk_free_unlock_clone() error path, for __sk_free() from sk_free() from
sk_free_unlock_clone() calls sock_inuse_add(-1).

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: 648845ab7e200993 ("sock: Move the socket inuse to namespace.")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/sock.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index c1601f75ec4b3..1b31e10181629 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2043,8 +2043,10 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
newsk->sk_prot_creator = prot;

/* SANITY */
- if (likely(newsk->sk_net_refcnt))
+ if (likely(newsk->sk_net_refcnt)) {
get_net(sock_net(newsk));
+ sock_inuse_add(sock_net(newsk), 1);
+ }
sk_node_init(&newsk->sk_node);
sock_lock_init(newsk);
bh_lock_sock(newsk);
@@ -2115,8 +2117,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
newsk->sk_err_soft = 0;
newsk->sk_priority = 0;
newsk->sk_incoming_cpu = raw_smp_processor_id();
- if (likely(newsk->sk_net_refcnt))
- sock_inuse_add(sock_net(newsk), 1);

/* Before updating sk_refcnt, we must commit prior changes to memory
* (Documentation/RCU/rculist_nulls.rst for details)
--
2.33.0