Subject: [PATCH 06/37] net: call cgroup_sk_alloc() earlier in sk_clone_lock()

From: Eric Dumazet <[email-masked]>
Date: Tue, 10 Oct 2017 19:12:33 -0700

[ Upstream commit c0576e3975084d4699b7bfef578613fb8e1144f6 ]

If for some reason, the newly allocated child need to be freed,
we will call cgroup_put() (via sk_free_unlock_clone()) while the
corresponding cgroup_get() was not yet done, and we will free memory
too soon.

Fixes: d979a39d7242 ("cgroup: duplicate cgroup reference when cloning sockets")
Signed-off-by: Eric Dumazet <[email-masked]>
Cc: Johannes Weiner <[email-masked]>
Cc: Tejun Heo <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/core/sock.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 0967da925022..e48424ddbc6b 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1674,6 +1674,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
 
 		sock_reset_flag(newsk, SOCK_DONE);
+		cgroup_sk_alloc(&newsk->sk_cgrp_data);
 
 		rcu_read_lock();
 		filter = rcu_dereference(sk->sk_filter);
@@ -1706,8 +1707,6 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
 		atomic64_set(&newsk->sk_cookie, 0);
 
 		mem_cgroup_sk_alloc(newsk);
-		cgroup_sk_alloc(&newsk->sk_cgrp_data);
-
 		/*
 		 * Before updating sk_refcnt, we must commit prior changes to memory
 		 * (Documentation/RCU/rculist_nulls.txt for details)
-- 
2.13.6