From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from oss.cyber.gouv.fr (oss.cyber.gouv.fr [51.159.188.251]) (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 E85BA3ED5D6; Tue, 6 Oct 2026 13:17:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=51.159.188.251 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791292630; cv=none; b=V3TMdpqv0yxYgHb/YieKYlo1x49zO2cRf8OI8AMldoZuN5uJojxX5kH7rxIfGR3DCpjtnDwYeXkmzXffi5Em9RomRXJ5R6a4guqhLjcwi+skWzB13xFJXefwodyRAB8madJpm8RZJKJbidX1GnqNye6D/8vgjRXerQIea9mGHAo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791292630; c=relaxed/simple; bh=nMLIv5b8FgYxUAJL70j13ODD8h60rrpKuPu4YZIEV6A=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=TB/FECdcSQklBQlrNlEm7qiD5g+p4GMzPGwxYAjHFZX+7N+Ohs6nBEGjMwlb8oON40RSbmRcPdRLYSEMol4poGgV8qyf0lZTKNhjTFq5RgPp/0Zn5FMGnyRRXqWAL09ZgxpmGJc1KaP+bc+DUITDJBRMcpO0gUxfQTrqP0Zi9jU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=oss.cyber.gouv.fr; spf=pass smtp.mailfrom=oss.cyber.gouv.fr; dkim=pass (2048-bit key) header.d=oss.cyber.gouv.fr header.i=@oss.cyber.gouv.fr header.b=LJwznXkd; arc=none smtp.client-ip=51.159.188.251 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=oss.cyber.gouv.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.cyber.gouv.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oss.cyber.gouv.fr header.i=@oss.cyber.gouv.fr header.b="LJwznXkd" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=oss.cyber.gouv.fr; s=default; h=Content-Transfer-Encoding:Content-Type: Message-ID:References:In-Reply-To:Subject:Cc:To:From:Date:MIME-Version: Reply-To:Sender:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID; bh=k5vD5U2vDHop2y93h5RObps/SJVwtXt/ikqi9pmsRyw=; b=LJwznXkd9feDS7KEE+0TKpJfvK UbX3SvWbrB/3yge0aTnVhNkc8Pgg13hP6lEQvfmsv9/rtioKOjB+4TgrxNg0w+/V8FfDsOidGdGJR /GVl5d2cgoIjIkmbi4OxjgIAU7b7fsY0+Arj82FoR8ibWTRjniUU1NNDylM1AE8Eti20fQf9F4n9t UkH7M0vFA5EzNEkE8elskAnt4qb8RGJTA0UIA9sspK5R+BA8sYGsJvFvZSoBC7viylvemfJmYzxPz 8nSLnCXDdB1+iRvtNjz3R5Lw+CV4kABmLoxM2YY6i1I76Z/RVUFZdsF1S2PWLyFeXSQeu+P6PoJSs TByaNAiw==; Received: from [::1] (port=50768 helo=pf-012.whm.fr-par.scw.cloud) by pf-012.whm.fr-par.scw.cloud with esmtpa (Exim 4.100.1) (envelope-from ) id 1xE52Z-0000000Fv2X-486s; Tue, 06 Oct 2026 15:17:06 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Tue, 06 Oct 2026 15:17:06 +0200 From: =?UTF-8?Q?J=C3=A9r=C3=A9my_Jean?= To: Pablo Neira Ayuso 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 In-Reply-To: References: <20261005200404.3544062-2-Jeremy.Jean@oss.cyber.gouv.fr> User-Agent: Roundcube Webmail/1.6.19 Message-ID: <9a9f2587b7bd37c8d03d0105cf968b25@oss.cyber.gouv.fr> X-Sender: jeremy.jean@oss.cyber.gouv.fr Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - pf-012.whm.fr-par.scw.cloud X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - oss.cyber.gouv.fr X-Get-Message-Sender-Via: pf-012.whm.fr-par.scw.cloud: authenticated_id: jeremy.jean@oss.cyber.gouv.fr X-Authenticated-Sender: pf-012.whm.fr-par.scw.cloud: jeremy.jean@oss.cyber.gouv.fr X-Source: X-Source-Args: X-Source-Dir: On 2026-10-06 01:05, Pablo Neira Ayuso wrote: > Hi, > > 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); >> >> rbe = container_of(interval->to, struct nft_rbtree_elem, ext); >> } else { >> -- >> 2.47.3 > > > Can you test this fix instead? Thanks Hello Pablo, Thanks for this improved fix. I replayed the reproducer I had that triggers the bug on the kernel that includes your patch, and I confirm that it fixes the UAF. Let me know if I could be of further assistance. Regards, Jérémy