net: Allow neigh contructor functions ability to modify the primary_key

[ Upstream commit 096b9854c04df86f03b38a97d40b6506e5730919 ]

Use n->primary_key instead of pkey to account for the possibility that a neigh
constructor function may have modified the primary_key value.

Signed-off-by: Jim Westfall <jwestfall@surrealistic.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jwestfall69

net/core/neighbour.c

@@ -508,7 +508,7 @@ struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 	if (atomic_read(&tbl->entries) > (1 << nht->hash_shift))
 		nht = neigh_hash_grow(tbl, nht->hash_shift + 1);
 
-	hash_val = tbl->hash(pkey, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
+	hash_val = tbl->hash(n->primary_key, dev, nht->hash_rnd) >> (32 - nht->hash_shift);
 
 	if (n->parms->dead) {
 		rc = ERR_PTR(-EINVAL);
@@ -520,7 +520,7 @@ struct neighbour *__neigh_create(struct neigh_table *tbl, const void *pkey,
 	     n1 != NULL;
 	     n1 = rcu_dereference_protected(n1->next,
 			lockdep_is_held(&tbl->lock))) {
-		if (dev == n1->dev && !memcmp(n1->primary_key, pkey, key_len)) {
+		if (dev == n1->dev && !memcmp(n1->primary_key, n->primary_key, key_len)) {
 			if (want_ref)
 				neigh_hold(n1);
 			rc = n1;