Subject: [PATCH 1/2] net: Allow neigh contructor functions ability to modify the primary_key

From: Jim Westfall <[email-masked]>
Date: Sat, 13 Jan 2018 16:00:18 -0800

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 <[email-masked]>
---
 net/core/neighbour.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index d1f5fe986edd..7f831711b6e0 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -532,7 +532,7 @@ 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);
@@ -544,7 +544,7 @@ 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;