netdev - [PATCH 6/8] netfilter: nft

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 23 Mar 2015 12:36:22 +0100
From:	Pablo Neira Ayuso <pablo@...filter.org>
To:	netfilter-devel@...r.kernel.org
Cc:	davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 6/8] netfilter: nft_rbtree: fix locking

From: Patrick McHardy <kaber@...sh.net>

Fix a race condition and unnecessary locking:

* the root rb_node must only be accessed under the lock in nft_rbtree_lookup()
* the lock is not needed in lookup functions in netlink context

Signed-off-by: Patrick McHardy <kaber@...sh.net>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nft_rbtree.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nft_rbtree.c b/net/netfilter/nft_rbtree.c
index 46214f2..2c75361 100644
--- a/net/netfilter/nft_rbtree.c
+++ b/net/netfilter/nft_rbtree.c
@@ -37,10 +37,11 @@ static bool nft_rbtree_lookup(const struct nft_set *set,
 {
 	const struct nft_rbtree *priv = nft_set_priv(set);
 	const struct nft_rbtree_elem *rbe, *interval = NULL;
-	const struct rb_node *parent = priv->root.rb_node;
+	const struct rb_node *parent;
 	int d;
 
 	spin_lock_bh(&nft_rbtree_lock);
+	parent = priv->root.rb_node;
 	while (parent != NULL) {
 		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 
@@ -158,7 +159,6 @@ static int nft_rbtree_get(const struct nft_set *set, struct nft_set_elem *elem)
 	struct nft_rbtree_elem *rbe;
 	int d;
 
-	spin_lock_bh(&nft_rbtree_lock);
 	while (parent != NULL) {
 		rbe = rb_entry(parent, struct nft_rbtree_elem, node);
 
@@ -173,11 +173,9 @@ static int nft_rbtree_get(const struct nft_set *set, struct nft_set_elem *elem)
 			    !(rbe->flags & NFT_SET_ELEM_INTERVAL_END))
 				nft_data_copy(&elem->data, rbe->data);
 			elem->flags = rbe->flags;
-			spin_unlock_bh(&nft_rbtree_lock);
 			return 0;
 		}
 	}
-	spin_unlock_bh(&nft_rbtree_lock);
 	return -ENOENT;
 }
 
-- 
1.7.10.4

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html