ipv4: Map neigh lookup keys in __ipv4_neigh_lookup_noref()

As discussed earlier,

From: Wang Han <[email protected]>
Date: Sat, 3 Feb 2018 03:28:35 +1400
Subject: [PATCH] ipv4: Map neigh lookup keys in __ipv4_neigh_lookup_noref()

Commit 6c16fa957e84 is an incorrect backport as we map the keys in struct __ipv4_neigh_lookup(), but the correct place to add the code is struct __ipv4_neigh_lookup_noref(), compared to upstream.

Fix it by moving the code, or fewer cases will be covered as __ipv4_neigh_lookup_noref() will be called unconditionally from __ipv4_neigh_lookup(), and it can be called from other places such as ip_output.c.

---
 include/net/arp.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

index 174014585ade..5d8c7990582f 100644
@@ -22,6 +22,9 @@ static inline struct neighbour *__ipv4_neigh_lookup_noref(struct net_device *dev
 	struct neighbour *n;
 	u32 hash_val;
 
+	if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
+		key = INADDR_ANY;
+
 	hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
 	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 	     n != NULL;

@@ -37,9 +40,6 @@ static inline struct neighbour *__ipv4_neigh_lookup(struct net_device *dev, u32
 {
 	struct neighbour *n;
 
-	if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
-		key = INADDR_ANY;
-
 	rcu_read_lock_bh();
 	n = __ipv4_neigh_lookup_noref(dev, key);
 	if (n && !atomic_inc_not_zero(&n->refcnt))

2.14.1

This is a note to let you know that I've just added the patch titled

ipv4: Map neigh lookup keys in __ipv4_neigh_lookup_noref()

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ipv4-map-neigh-lookup-keys-in-__ipv4_neigh_lookup_noref.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Wang Han <[email protected]>
Date: Fri, 2 Feb 2018 23:06:51 +0800
Subject: ipv4: Map neigh lookup keys in __ipv4_neigh_lookup_noref()
To: [email protected]
Message-ID: <[email protected]>

From: Wang Han <[email protected]>

Commit 6c16fa957e84 is an incorrect backport as we map the keys in struct __ipv4_neigh_lookup(), but the correct place to add the code is struct __ipv4_neigh_lookup_noref(), compared to upstream.

Fix it by moving the code, or fewer cases will be covered as __ipv4_neigh_lookup_noref() will be called unconditionally from __ipv4_neigh_lookup(), and it can be called from other places such as ip_output.c.

---
 include/net/arp.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

@@ -22,6 +22,9 @@ static inline struct neighbour *__ipv4_n
 	struct neighbour *n;
 	u32 hash_val;
 
+	if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
+		key = INADDR_ANY;
+
 	hash_val = arp_hashfn(key, dev, nht->hash_rnd[0]) >> (32 - nht->hash_shift);
 	for (n = rcu_dereference_bh(nht->hash_buckets[hash_val]);
 	     n != NULL;

@@ -37,9 +40,6 @@ static inline struct neighbour *__ipv4_n
 {
 	struct neighbour *n;
 
-	if (dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))
-		key = INADDR_ANY;
-
 	rcu_read_lock_bh();
 	n = __ipv4_neigh_lookup_noref(dev, key);
 	if (n && !atomic_inc_not_zero(&n->refcnt))

Patches currently in stable-queue which might be from [email protected] are

queue-3.18/ipv4-map-neigh-lookup-keys-in-__ipv4_neigh_lookup_noref.patch