From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9DC03EC82D; Mon, 5 Oct 2026 21:42:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791236543; cv=none; b=eaiQow/tHIZAKjBNEccY7PLIbt4wJ/uHreh6R/WQVVxPOithbuPCDPGLeqZUqQQ8iQdVntPTMWkoGDN95+0X1CjytGVJnt+lQUhgmqTkO5M0oza/jUjF3juSejoL6ESpqlEqC2s9Xi9NSenkM6MOUZZjQqdjTEr41zNwjZODuHg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791236543; c=relaxed/simple; bh=5ufy/bfmVzzplXqdx7/75xm5HaujQZ4TcWt4llsdZPw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ZZtFjX6Hnvk8BOX3PGTWYBJ9559CPgiOTYV44fVfcFryPpInzc4sVn7bFInLwglSxoxe2+ir+PRTKRhkCR77oisEP7VVpqHEv0PHEohgjdf7ouT/9gKg5WzMHKabgMwq++p+lmGtRLc5AfFH5QOCxDhWI5/H6f0kC+XlFOH/vdo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=BgCng0/4; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="BgCng0/4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1791236539; bh=tAtcUUT2qjyAeZ31TLI3ERcF0M8NpLZuPpj95AkTDEU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BgCng0/4d0s8qaTZYdigR7Tb9b8Td9/91DqaxH9v8UPASQIJ7RKxYncG3uaM5tYd4 1vjryNzNP9gC8GwbIVqVp+r8nYrE48dG7k3sOfmvZEMhz1xmRqLxZ42tzphgShyDDY 1eKnrYMzaxt72lz1uC6MaQX+AGudYVlnl0LZYH1saQPt79vnb4lxP+bdFM+eBiVBkD cnAQQV7WC1snlrq1at34Kg0P/a/aS5ZlKiq5MWY6d0OBJ/BHTFSiUnkzp0/AZmGDIX CaOiVkk4BwjlgBWm6c0RBxMACSU/fdjJmRcXcG+kI+SWUI8a7NSbEy9D4CsKVrhDGC 3naOjiClxOjWw== Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id 13C4D60052; Mon, 5 Oct 2026 23:42:19 +0200 (CEST) Date: Mon, 5 Oct 2026 23:42:16 +0200 From: Pablo Neira Ayuso To: =?utf-8?B?SsOpcsOpbXk=?= Jean Cc: Florian Westphal , Phil Sutter , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH nf] netfilter: nft_set_rbtree: reject expired interval ends Message-ID: References: <20261005200404.3544062-2-Jeremy.Jean@oss.cyber.gouv.fr> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Mon, Oct 05, 2026 at 11:20:57PM +0200, Pablo Neira Ayuso wrote: > On Mon, Oct 05, 2026 at 08:04:05PM +0000, Jérémy Jean wrote: > > Consider two ranges in a netfilter verdict map: > > * keys 10-19 accept packets, and > > * keys 30-39 jump to chain 'victim'. > > Now, delete the end marker at 20. The lookup array now uses element 30 > > as the first range's end, so an INTERVAL_END query for key 15 returns > > element 30, including its jump verdict and chain pointer. This can make > > KASAN reports a UAF after the GC releases reference chain for 30 that > > has expired: > > > > BUG: KASAN: slab-use-after-free in nft_verdict_dump+0xdd/0x110 > > Read of size 8 at addr ff110000009dfb58 by task repro/50 > > ... > > Call Trace: > > ... > > nft_verdict_dump+0xdd/0x110 > > nft_data_dump+0x4d/0x80 > > nf_tables_fill_setelem+0x30b/0x8a0 > > ? __asan_memcpy+0x3c/0x60 > > nf_tables_fill_setelem_info+0x1b0/0x200 > > nft_get_set_elem+0x3fd/0x4b0 > > ... > > Freed by task 24: > > ... > > kfree+0x1a5/0x280 > > nf_tables_trans_destroy_work+0x2cb/0x520 > > > > Reject expired endpoints in nft_rbtree_get() before returning them. > > > > Fixes: 2aa34191f06f ("netfilter: nft_set_rbtree: use binary search array in get command") > > Cc: stable@vger.kernel.org > > Assisted-by: LLM > > Signed-off-by: Jérémy Jean > > --- > > net/netfilter/nft_set_rbtree.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c > > index 9894832..1fd9cbe 100644 > > --- a/net/netfilter/nft_set_rbtree.c > > +++ b/net/netfilter/nft_set_rbtree.c > > @@ -187,6 +187,8 @@ nft_rbtree_get(const struct net *net, const struct nft_set *set, > > if (flags & NFT_SET_ELEM_INTERVAL_END) { > > if (!interval->to) > > return NULL; > > + if (nft_set_elem_expired(interval->to)) > > + return ERR_PTR(-ENOENT); > > End elements carry no timeout set extension. And nf_tables_getsetelem() is called under RCU read side lock, and elements are released after RCU grace period. This patch is papering the problem. > > rbe = container_of(interval->to, struct nft_rbtree_elem, ext); > > } else { > > -- > > 2.47.3 > >