From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from jabberwock.ucw.cz (jabberwock.ucw.cz [46.255.230.98]) (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 B7C2685291 for ; Wed, 20 Mar 2024 18:59:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.255.230.98 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710961181; cv=none; b=d5G+Vk3Bo6lhW6j9NNHe8+hXQk6fH5fGiejFUb8/jnMOqJ5wsfjZUh6kC8qcOo9RDW5U3f80YvKAa0zafa9tCKuGIBoBixdk6hXyv5vwDmH5DDaQqhe6SCV2oZIEuHSi8y6xNGvVp6Qs1Tn01Ma88QMKT7epAbbqLKw/EwKT1cU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710961181; c=relaxed/simple; bh=RbZrfg2enwvomoRc2bu6a3WxV/74o7lRtsEbX7U9R6s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=uuCN9ltADDmSV/ut2pq1MKLa/yYBvZtaD0Alh8rNwBGBvJbKRdAnB0WNXS8uw85ztdar0G1tZt3qmRgrKrzryDQHUC2ML9LvOQoFbANoKBMkUSHeQr3nD81sK/9hOL7e4VD9XzC40UQr6qQsPIeszHEiVkwz9f6sL5VDVX2PShA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ucw.cz; spf=pass smtp.mailfrom=ucw.cz; dkim=pass (1024-bit key) header.d=ucw.cz header.i=@ucw.cz header.b=c732I0DS; arc=none smtp.client-ip=46.255.230.98 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ucw.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ucw.cz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ucw.cz header.i=@ucw.cz header.b="c732I0DS" Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 4C3B71C007F; Wed, 20 Mar 2024 19:59:35 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ucw.cz; s=gen1; t=1710961175; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=OR/WXQvDApRGoduyJZRKiARfSeeGYfAfVOZRHxcAXMs=; b=c732I0DSTVxrrt4fXjYUwxa2dWiGnoL6N44Yhcndm131wyMqFmG1qCZrNiUvR64YugOxbI iq/zgXewzGdVgP6MlnxRIsewYut+zD39LPLwCup0zIpwZ7vvw7TrZnDt7g5kyQpcjuvDSF Q0n2ms0mzTETHPt6qGrKxZwiIIQ56IE= Date: Wed, 20 Mar 2024 19:59:34 +0100 From: Pavel Machek To: Lee Jones Cc: Kees Cook , Luis Chamberlain , Michal Hocko , cve@kernel.org, linux-kernel@vger.kernel.org, Joel Granados , Greg Kroah-Hartman Subject: Re: CVE-2023-52596: sysctl: Fix out of bounds access for empty sysctl registers Message-ID: References: <2024030645-CVE-2023-52596-b98e@gregkh> <20240312091730.GU86322@google.com> <20240312154910.GC1522089@google.com> <202403121431.55E67E201@keescook> <20240313080132.GD1522089@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="I/sz2lbjHdt9EdnG" Content-Disposition: inline In-Reply-To: <20240313080132.GD1522089@google.com> --I/sz2lbjHdt9EdnG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > > I have tried to argue before that it's up to the core kernel code to Do > > The Right Thing, even in the face of crappy out-of-tree code, so to me, > > since this is a (very very very limited) weakness in the core kernel > > code, give it a CVE. > >=20 > > My attempt at a CVSS for it yields a 3.4 overall: > > AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:X > > https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=3DAV:L/AC:H= /PR:H/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:X&version=3D3.1 >=20 > Thank you Luis and Kees for your input. Your efforts are very much > appreciated. I have read and digested everyone's points. >=20 > Since no one (including myself) is willing to conclude that this > represents _zero_ risk, the allocation will not be rescinded. In our Well, if you insist this is real risk (it is not) would you be so kind at at least fix the "vulnerability" description? "Module can trigger BUG_ON in kernel" would be suitable, according to the discussion. Current description is copy/paste nonsense :-(. Best regards, Pavel https://nvd.nist.gov/vuln/detail/CVE-2023-52596 Description In the Linux kernel, the following vulnerability has been resolved: sysctl: Fix out of bounds access for empty sysctl registers When registering tables to the sysctl subsystem there is a check to see if header is a permanently empty directory (used for mounts). This check evaluates the first element of the ctl_table. This results in an out of bounds evaluation when registering empty directories. The function register_sysctl_mount_point now passes a ctl_table of size 1 instead of size 0. It now relies solely on the type to identify a permanently empty register. Make sure that the ctl_table has at least one element before testing for permanent emptiness. --=20 People of Russia, stop Putin before his war on Ukraine escalates. --I/sz2lbjHdt9EdnG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRPfPO7r0eAhk010v0w5/Bqldv68gUCZfsyFgAKCRAw5/Bqldv6 8rlMAJ9zwEI6Bq3CaVa2JWurCHbkDkaa/QCfZVlLm3F+LvACRfwV8gjBUUT3hjo= =988t -----END PGP SIGNATURE----- --I/sz2lbjHdt9EdnG--