1 files changed, 36 insertions, 5 deletions

diff --git a/net/core/sock.c b/net/core/sock.c
index 6354863b1c68..bbb25be7ddfe 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -631,7 +631,7 @@ set_rcvbuf:
 
         case SO_TIMESTAMPING:
                 if (val & ~SOF_TIMESTAMPING_MASK) {
-                        ret = EINVAL;
+                        ret = -EINVAL;
                         break;
                 }
                 sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
@@ -919,13 +919,19 @@ static inline void sock_lock_init(struct sock *sk)
                         af_family_keys + sk->sk_family);
 }
 
+/*
+ * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
+ * even temporarly, because of RCU lookups. sk_node should also be left as is.
+ */
 static void sock_copy(struct sock *nsk, const struct sock *osk)
 {
 #ifdef CONFIG_SECURITY_NETWORK
         void *sptr = nsk->sk_security;
 #endif
-
-        memcpy(nsk, osk, osk->sk_prot->obj_size);
+        BUILD_BUG_ON(offsetof(struct sock, sk_copy_start) !=
+                     sizeof(osk->sk_node) + sizeof(osk->sk_refcnt));
+        memcpy(&nsk->sk_copy_start, &osk->sk_copy_start,
+               osk->sk_prot->obj_size - offsetof(struct sock, sk_copy_start));
 #ifdef CONFIG_SECURITY_NETWORK
         nsk->sk_security = sptr;
         security_sk_clone(osk, nsk);
@@ -939,8 +945,23 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
         struct kmem_cache *slab;
 
         slab = prot->slab;
-        if (slab != NULL)
-                sk = kmem_cache_alloc(slab, priority);
+        if (slab != NULL) {
+                sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
+                if (!sk)
+                        return sk;
+                if (priority & __GFP_ZERO) {
+                        /*
+                         * caches using SLAB_DESTROY_BY_RCU should let
+                         * sk_node.next un-modified. Special care is taken
+                         * when initializing object to zero.
+                         */
+                        if (offsetof(struct sock, sk_node.next) != 0)
+                                memset(sk, 0, offsetof(struct sock, sk_node.next));
+                        memset(&sk->sk_node.pprev, 0,
+                               prot->obj_size - offsetof(struct sock,
+                                                         sk_node.pprev));
+                }
+        }
         else
                 sk = kmalloc(prot->obj_size, priority);
 
@@ -1125,6 +1146,11 @@ struct sock *sk_clone(const struct sock *sk, const gfp_t priority)
 
                 newsk->sk_err      = 0;
                 newsk->sk_priority = 0;
+                /*
+                 * Before updating sk_refcnt, we must commit prior changes to memory
+                 * (Documentation/RCU/rculist_nulls.txt for details)
+                 */
+                smp_wmb();
                 atomic_set(&newsk->sk_refcnt, 2);
 
                 /*
@@ -1840,6 +1866,11 @@ void sock_init_data(struct socket *sock, struct sock *sk)
 
         sk->sk_stamp = ktime_set(-1L, 0);
 
+        /*
+         * Before updating sk_refcnt, we must commit prior changes to memory
+         * (Documentation/RCU/rculist_nulls.txt for details)
+         */
+        smp_wmb();
         atomic_set(&sk->sk_refcnt, 1);
         atomic_set(&sk->sk_wmem_alloc, 1);
         atomic_set(&sk->sk_drops, 0);