From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lamorak.hansenpartnership.com (lamorak.hansenpartnership.com [198.37.111.173]) (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 B2290111A8; Tue, 11 Mar 2025 17:46:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.37.111.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741715187; cv=none; b=ctFtGz1SndOs3wgqfxyj8YZGRZXO3t1vjocyGb6rMK714iZkER4ggVM08wrJy3E9gEZdwHQwLBUYa8zNa9BUsSJTkDBa7puSK6oJno8J1v/LmXqZIRuGy9s3V++j6ocOGxcmyq8Rh8Kn6lbXt+cMPw3Q0dDV4ePz8dGS4OnTVl0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741715187; c=relaxed/simple; bh=j039Bd3D9yx2w6NvnDqzqrIBiV1JbpR4DnZ/G13n3zs=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=ixTEYBL9kDcjp9KW8HOAyKT8/CLHqwXFDF7rL17mKTltM7ZId30BqKFEEORu1GugWkwgVJvlnJUW99Hj2xd+n4BZ4UuoSWUXPiKKnSEE+f5psapcSO4Be2qtvyrlDwj7mmWYSvLA8xQGkmdjvTCF0I+yDKZ7Y4U4JtHxPvS4ucQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=HansenPartnership.com; spf=pass smtp.mailfrom=HansenPartnership.com; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b=CzHLzcqO; arc=none smtp.client-ip=198.37.111.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=HansenPartnership.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="CzHLzcqO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=hansenpartnership.com; s=20151216; t=1741715184; bh=j039Bd3D9yx2w6NvnDqzqrIBiV1JbpR4DnZ/G13n3zs=; h=Message-ID:Subject:From:To:Date:In-Reply-To:References:From; b=CzHLzcqO9yjRGvSxL60Ze4Z0hwtz7HXs98VwRm2VlUoQ/C7/xRo4F4wkZNgOdbpdp WoGjl4GCLALlIMnBfBckbPFJy3ShMW27xVKOBTLR7vS3QWTMO6RypfDijQRLAGPQcc tpMJ4vMzZsuwlDTt+Q29t6GicOXDiABYojRy/ZkY= Received: from lingrow.int.hansenpartnership.com (unknown [IPv6:2601:5c4:4302:c21::a774]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lamorak.hansenpartnership.com (Postfix) with ESMTPSA id 3E8C91C02CF; Tue, 11 Mar 2025 13:46:24 -0400 (EDT) Message-ID: <4ac2a24c748c974609b19d810a797e4a3dce3e6a.camel@HansenPartnership.com> Subject: Re: apparmor NULL pointer dereference on resume [efivarfs] From: James Bottomley To: Al Viro Cc: Christian Brauner , Ard Biesheuvel , Ryan Lee , Malte =?ISO-8859-1?Q?Schr=F6der?= , linux-security-module@vger.kernel.org, apparmor , linux-efi@vger.kernel.org, John Johansen , "jk@ozlabs.org" , linux-fsdevel@vger.kernel.org Date: Tue, 11 Mar 2025 13:46:23 -0400 In-Reply-To: <20250311171534.GQ2023217@ZenIV> References: <465d1d23-3b36-490e-b0dd-74889d17fa4c@tnxip.de> <20250311-visite-rastplatz-d1fdb223dc10@brauner> <814a257530ad5e8107ce5f48318ab43a3ef1f783.camel@HansenPartnership.com> <20250311-trunk-farben-fe36bebe233a@brauner> <78a59e2a5012bfb2d6a653782ab346b44b211102.camel@HansenPartnership.com> <20250311171534.GQ2023217@ZenIV> Autocrypt: addr=James.Bottomley@HansenPartnership.com; prefer-encrypt=mutual; keydata=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 cb6tmt+BSuR8IUhU1gUCZag0LwUJDwLkSQCBdiAEGRMIAB0WIQTnYEDbdso9F2cI+arnQslM7pishQUCWme25gAKCRDnQslM7pishdi9AQDyOvLYOBkylBqiTlJrMnGCCsWgGZwPpKq3e3s7JQ/xBAEAlx29pPY5z0RLyIDUsjf9mtkSNTaeaQ6TIjDrFa+8XH8JEIFK5HwhSFTWkasH/j7LL9WH9dRfwfTwuMMj1/KGzjU/4KFIu4uKxDaevKpGS7sDx4F56mafCdGD8u4+ri6bJr/3mmuzIdyger0vJdRlTrnpX3ONXvR57p1JHgCljehE1ZB0RCzIk0vKhdt8+CDBQWfKbbKBTmzA7wR68raMQb2D7nQ9d0KXXbtr7Hag29yj92aUAZ/sFoe9RhDOcRUptdYyPKU1JHgJyc0Z7HwNjRSJ4lKJSKP+Px0/XxT3gV3LaDLtHuHa2IujLEAKcPzTr5DOV+xsgA3iSwTYI6H5aEe+ZRv/rA4sdjqRiVpo2d044aCUFUNQ3PiIHPAZR3KK5O64m6+BJMDXBvgSsMy4VgRaZ7clEggqhkjOPQMBBwIDBMfuMuE+PECbOoYjkD0Teno7TDbcgxJNgPV7Y2lQbNBnexMLOEY6/xJzRi1Xm/o9mOyZ+VIj8h4G5V/eWSntNkwDAQgHiQE8BBgBCAAmAhsMFiEE1WBuc8i0YnG+rZrfgUrkfCFIVNYFAmWoNBwFCQ8C4/cACgkQgUrkfCFIVNZs4AgAnIjU1QEPLdpotiy3X01sKUO+hvcT3/Cd6g55sJyKJ5/U0o3f8fdSn6MWPhi1m62zbAxcLJFiTZ3OWNCZAMEvwHrXFb684Ey6yImQ9gm2dG2nVuCzr1+9gIaMSBeZ+4kUJqhdWSJjrNLQG38GbnBuYOJUD+x6oJ2AT10/mQfBVZ3qWDQXr/je2TSf0OIXaWyG6meG5yTqOEv0eaTH22yBb1nbodoZkmlMMb56jzRGZuorhFE06 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 8mT2Eh9SkH+YVOmaKsajgZgrBxA7fWmGoxXswEVxJIFj3vW7yNc0C5HaUdYa5iGOMs4kg2ht4s7yy7NRQuh7BifWjo6BQ6k4S1H+6axZucxhSV1L6zN9d+lr3Xo/vy1unzA== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.50.3 Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Tue, 2025-03-11 at 17:15 +0000, Al Viro wrote: > On Tue, Mar 11, 2025 at 12:20:05PM -0400, James Bottomley wrote: >=20 > > That's the way it's supposed to work, yes.=C2=A0 However, if we move to > > an always persistent superblock and mnt, I was thinking there'd > > have to be an indicator in the sfi about whether the variables were > > reflected or not. >=20 > Just have a pointer to superblock set at ->get_tree() and cleared at > the very beginning of ->kill_sb(), then have notifier bugger off if > that thing's NULL or if atomic_inc_not_zero(sb->s_active) fails > (rcu_read_lock() is sufficient for memory safety of that).=C2=A0 And > do deactivate_super() when you are done. OK that works, thanks! > That'll give you exclusion with umount.=C2=A0 As for the rest of that... > fuck it, just have kern_mount()/kern_unmount() inside that. > How hot do you expect that notifier chain to be? The notifier chain itself is somewhat active, but the notifications we care about occur once on resume from hibernate (so very few, if any). > Or screw playing with open/iterate_dir, but that'll need some > thinking - > theoretically everything you need is already accessible, but direct > access to ->d_lock/->d_sib in there is almost certainly not the right > level of abstraction.=C2=A0 We already have similar bits and pieces > in autofs and ceph, and it's just a matter of figuring out a good > set of primitives. I'll probably stick to getting it to work for now ... the refactoring can come later. Regards, James