net: Introduce sk_clone_lock() error path routine

When handling problems in cloning a socket with the sk_clone_locked()
function we need to perform several steps that were open coded in it and
its callers, so introduce a routine to avoid this duplication:
sk_free_unlock_clone().

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/net-ui6laqkotycunhtmqryl9bfx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 12 insertions, 10 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index e7d74940e863..f6fd79f33097 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1539,11 +1539,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
                         is_charged = sk_filter_charge(newsk, filter);
 
                 if (unlikely(!is_charged || xfrm_sk_clone_policy(newsk, sk))) {
-                        /* It is still raw copy of parent, so invalidate
-                         * destructor and make plain sk_free() */
-                        newsk->sk_destruct = NULL;
-                        bh_unlock_sock(newsk);
-                        sk_free(newsk);
+                        sk_free_unlock_clone(newsk);
                         newsk = NULL;
                         goto out;
                 }
@@ -1592,6 +1588,16 @@ out:
 }
 EXPORT_SYMBOL_GPL(sk_clone_lock);
 
+void sk_free_unlock_clone(struct sock *sk)
+{
+        /* It is still raw copy of parent, so invalidate
+         * destructor and make plain sk_free() */
+        sk->sk_destruct = NULL;
+        bh_unlock_sock(sk);
+        sk_free(sk);
+}
+EXPORT_SYMBOL_GPL(sk_free_unlock_clone);
+
 void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
 {
         u32 max_segs = 1;
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
index d20d948a98ed..e267e6f4c9a5 100644
--- a/net/dccp/minisocks.c
+++ b/net/dccp/minisocks.c
@@ -119,11 +119,7 @@ struct sock *dccp_create_openreq_child(const struct sock *sk,
                  * Activate features: initialise CCIDs, sequence windows etc.
                  */
                 if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
-                        /* It is still raw copy of parent, so invalidate
-                         * destructor and make plain sk_free() */
-                        newsk->sk_destruct = NULL;
-                        bh_unlock_sock(newsk);
-                        sk_free(newsk);
+                        sk_free_unlock_clone(newsk);
                         return NULL;
                 }
                 dccp_init_xmit_timers(newsk);