[PATCH 4.4 71/74] net: Allow neigh contructor functions ability to modify the primary_key

From: Greg Kroah-Hartman
Date: Mon Jan 29 2018 - 15:39:19 EST


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

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

From: Jim Westfall <jwestfall@xxxxxxxxxxxxxxxx>


[ 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@xxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/core/neighbour.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -496,7 +496,7 @@ struct neighbour *__neigh_create(struct
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);
@@ -508,7 +508,7 @@ struct neighbour *__neigh_create(struct
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;