From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C4FE0C61D9C for ; Tue, 21 Nov 2023 12:13:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234612AbjKUMNt (ORCPT ); Tue, 21 Nov 2023 07:13:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234206AbjKUMNs (ORCPT ); Tue, 21 Nov 2023 07:13:48 -0500 Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 34986183; Tue, 21 Nov 2023 04:13:45 -0800 (PST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: gregkh@linuxfoundation.org, sashal@kernel.org, stable@vger.kernel.org Subject: [PATCH -stable,5.4 06/26] netfilter: nft_set_rbtree: fix overlap expiration walk Date: Tue, 21 Nov 2023 13:13:13 +0100 Message-Id: <20231121121333.294238-7-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20231121121333.294238-1-pablo@netfilter.org> References: <20231121121333.294238-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Florian Westphal commit f718863aca469a109895cb855e6b81fff4827d71 upstream. The lazy gc on insert that should remove timed-out entries fails to release the other half of the interval, if any. Can be reproduced with tests/shell/testcases/sets/0044interval_overlap_0 in nftables.git and kmemleak enabled kernel. Second bug is the use of rbe_prev vs. prev pointer. If rbe_prev() returns NULL after at least one iteration, rbe_prev points to element that is not an end interval, hence it should not be removed. Lastly, check the genmask of the end interval if this is active in the current generation. Fixes: c9e6978e2725 ("netfilter: nft_set_rbtree: Switch to node list walk for overlap detection") Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nft_set_rbtree.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c index 928288138a51..f456db3d786d 100644 --- a/net/netfilter/nft_set_rbtree.c +++ b/net/netfilter/nft_set_rbtree.c @@ -216,29 +216,37 @@ static void *nft_rbtree_get(const struct net *net, const struct nft_set *set, static int nft_rbtree_gc_elem(const struct nft_set *__set, struct nft_rbtree *priv, - struct nft_rbtree_elem *rbe) + struct nft_rbtree_elem *rbe, + u8 genmask) { struct nft_set *set = (struct nft_set *)__set; struct rb_node *prev = rb_prev(&rbe->node); - struct nft_rbtree_elem *rbe_prev = NULL; + struct nft_rbtree_elem *rbe_prev; struct nft_set_gc_batch *gcb; gcb = nft_set_gc_batch_check(set, NULL, GFP_ATOMIC); if (!gcb) return -ENOMEM; - /* search for expired end interval coming before this element. */ + /* search for end interval coming before this element. + * end intervals don't carry a timeout extension, they + * are coupled with the interval start element. + */ while (prev) { rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node); - if (nft_rbtree_interval_end(rbe_prev)) + if (nft_rbtree_interval_end(rbe_prev) && + nft_set_elem_active(&rbe_prev->ext, genmask)) break; prev = rb_prev(prev); } - if (rbe_prev) { + if (prev) { + rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node); + rb_erase(&rbe_prev->node, &priv->root); atomic_dec(&set->nelems); + nft_set_gc_batch_add(gcb, rbe_prev); } rb_erase(&rbe->node, &priv->root); @@ -320,7 +328,7 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set, /* perform garbage collection to avoid bogus overlap reports. */ if (nft_set_elem_expired(&rbe->ext)) { - err = nft_rbtree_gc_elem(set, priv, rbe); + err = nft_rbtree_gc_elem(set, priv, rbe, genmask); if (err < 0) return err; -- 2.30.2