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 92E5C36D4E4; Sun, 8 Mar 2026 10:43:04 +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=1772966587; cv=none; b=bWKxM9kbwLDTkGDAi3+mJ0XOU4i9ZXuG70dgK8xS9e+mxwBvgnLx+GD+l6pWPWyv8FjBCjVbPA8+AjPDkHWSNj/Yv+4dBp5WaiigRiK0WC4KfORQhDZ+aq/SFeotsw1g24ILq/GWC2UTHknwlJ+Z52+LgWz86gtkEsqUrSnM5NM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772966587; c=relaxed/simple; bh=y02TfbcEwGKQePAuEZIBamlBhc6UIiF+PhEqTAb8ZWg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dzNcYsXxMYPBCAc3RWpLFxSCRbUq04lW1p+5rNeRSBw1mWBG/YsEGv48iAgEhE5Yc+eYiAkHAjvwf9dv8puhDba93RJe8lKvh3f//9Ndv+fTBgdN6IUSESzSgCuXfVnmYiqB8fLjmRBJMs64vIgx56vRYo5qW8jahZf6NmobhQo= 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=sTaDHGsj; 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="sTaDHGsj" Received: from netfilter.org (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with UTF8SMTPSA id 142E660521; Sun, 8 Mar 2026 11:43:02 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1772966582; bh=+M+S7zGFiZKb8nqyORaqH9S+h5OjmBDWiY/9ubOO6rw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sTaDHGsjSoLcXyrme51C/4cfZZCderlwRHxr64fk+J4kApYHkRXub3jVr6luLk5vz FVSBRIX/t6tpvs2zKGZy0if4XGtZdw/VcU54HZ4RB7DWbJ6Hw1XmJyfYpd3TWfmXYD veJ4TmEGq4eYaJLIU2N5Se+ODfejqPJX9UqEwrjevzTPqxT96vOkFD70bjcCDC0c1U ptx+7IYl6+4FzdiXV2546OfVSF2ft093nvIV002In9ze2GMr/4rytaHrv7BDK+9HEY T0AGnpbX/R2GzcQNfp3/2s62e+lZNmsUSAu98fHQ1XDzfI8DtmIS7S15v7qI6/nEJl Du/L6epu1SFZg== Date: Sun, 8 Mar 2026 11:42:59 +0100 From: Pablo Neira Ayuso To: Florian Westphal Cc: Hyunwoo Kim , phil@nwl.cc, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org Subject: Re: [PATCH net] netfilter: ctnetlink: validate CTA_EXPECT_NAT_DIR to prevent OOB access Message-ID: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Sat, Mar 07, 2026 at 07:01:07PM +0100, Florian Westphal wrote: > Hyunwoo Kim wrote: > > ctnetlink_parse_expect_nat() assigns the user-supplied > > CTA_EXPECT_NAT_DIR value directly to exp->dir without validating that it > > is within the valid range (0 to IP_CT_DIR_MAX-1). When > > nf_nat_sip_expected() later uses exp->dir as an index into > > ct->master->tuplehash[], an out-of-bounds array access occurs. > > > > For example, with exp->dir = 100, the access at > > ct->master->tuplehash[100] reads 5600 bytes past the start of a > > 320-byte nf_conn object, causing a slab-out-of-bounds read confirmed by > > UBSAN. > > > > Validate exp->dir against IP_CT_DIR_MAX before accepting it. > > I would prefer a fix for exp_nat_nla_policy so netlink policy validation > can handle this for us. > > [CTA_EXPECT_NAT_DIR] = NLA_POLICY_MAX(NLA_BE32, IPCT_DIR_MAX), > > .. should do it. Might make sense to check all other attrs while at it. Agreed.