[PATCH 4.9 05/39] net: call cgroup_sk_alloc() earlier in sk_clone_lock()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@google.com>


[ 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 <edumazet@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/sock.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1526,6 +1526,7 @@ struct sock *sk_clone_lock(const struct
 		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
 
 		sock_reset_flag(newsk, SOCK_DONE);
+		cgroup_sk_alloc(&newsk->sk_cgrp_data);
 		skb_queue_head_init(&newsk->sk_error_queue);
 
 		filter = rcu_dereference_protected(newsk->sk_filter, 1);
@@ -1560,8 +1561,6 @@ struct sock *sk_clone_lock(const struct
 		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)