From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: [PATCH 1/5] netfilter: nft_rbtree: fix locking Date: Sat, 21 Mar 2015 15:19:14 +0000 Message-ID: <1426951158-18168-2-git-send-email-kaber@trash.net> References: <1426951158-18168-1-git-send-email-kaber@trash.net> Cc: netfilter-devel@vger.kernel.org To: pablo@netfilter.org Return-path: Received: from stinky.trash.net ([213.144.137.162]:46420 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751314AbbCUPTW (ORCPT ); Sat, 21 Mar 2015 11:19:22 -0400 In-Reply-To: <1426951158-18168-1-git-send-email-kaber@trash.net> Sender: netfilter-devel-owner@vger.kernel.org List-ID: 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 --- 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; } -- 2.1.0