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 A2E36E95A8E for ; Mon, 9 Oct 2023 13:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377209AbjJINhm (ORCPT ); Mon, 9 Oct 2023 09:37:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1377230AbjJINhk (ORCPT ); Mon, 9 Oct 2023 09:37:40 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 559319C for ; Mon, 9 Oct 2023 06:37:39 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55975C433C9; Mon, 9 Oct 2023 13:37:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696858658; bh=jD1vH9+3WX+0A+gfjHqu2MB/jqLikYlc+/Ic3v3XpYU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Crpo3QfUrW6w4Y8mSNXxDEDJQWli4VZFHn/8a28gDydnBZTySQdOS4Q71481BWves 61kgw+ajt5hChqJ69G5zukBR9pY3Psglo+nRU5SzqD7kQbQq+xJvzK49BTICbmUmji yxteATUBRlBC5xanUQUYubeuMcUVxsP+dDLvLjVY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pablo Neira Ayuso , Florian Westphal , Sasha Levin Subject: [PATCH 5.10 032/226] netfilter: nf_tables: fix memleak when more than 255 elements expired Date: Mon, 9 Oct 2023 14:59:53 +0200 Message-ID: <20231009130127.615913286@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231009130126.697995596@linuxfoundation.org> References: <20231009130126.697995596@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Florian Westphal commit cf5000a7787cbc10341091d37245a42c119d26c5 upstream. When more than 255 elements expired we're supposed to switch to a new gc container structure. This never happens: u8 type will wrap before reaching the boundary and nft_trans_gc_space() always returns true. This means we recycle the initial gc container structure and lose track of the elements that came before. While at it, don't deref 'gc' after we've passed it to call_rcu. Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane") Reported-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- include/net/netfilter/nf_tables.h | 2 +- net/netfilter/nf_tables_api.c | 10 ++++++++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index bbe472c07d07e..5619642b9ad47 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1525,7 +1525,7 @@ struct nft_trans_gc { struct net *net; struct nft_set *set; u32 seq; - u8 count; + u16 count; void *priv[NFT_TRANS_GC_BATCHCOUNT]; struct rcu_head rcu; }; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 9fc302a6836ba..32c97cc87ddc2 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8124,12 +8124,15 @@ static int nft_trans_gc_space(struct nft_trans_gc *trans) struct nft_trans_gc *nft_trans_gc_queue_async(struct nft_trans_gc *gc, unsigned int gc_seq, gfp_t gfp) { + struct nft_set *set; + if (nft_trans_gc_space(gc)) return gc; + set = gc->set; nft_trans_gc_queue_work(gc); - return nft_trans_gc_alloc(gc->set, gc_seq, gfp); + return nft_trans_gc_alloc(set, gc_seq, gfp); } void nft_trans_gc_queue_async_done(struct nft_trans_gc *trans) @@ -8144,15 +8147,18 @@ void nft_trans_gc_queue_async_done(struct nft_trans_gc *trans) struct nft_trans_gc *nft_trans_gc_queue_sync(struct nft_trans_gc *gc, gfp_t gfp) { + struct nft_set *set; + if (WARN_ON_ONCE(!lockdep_commit_lock_is_held(gc->net))) return NULL; if (nft_trans_gc_space(gc)) return gc; + set = gc->set; call_rcu(&gc->rcu, nft_trans_gc_trans_free); - return nft_trans_gc_alloc(gc->set, 0, gfp); + return nft_trans_gc_alloc(set, 0, gfp); } void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans) -- 2.40.1