From: Kees Cook <keescook@chromium.org>
To: Kevin Locke <kevin@kevinlocke.name>,
John Johansen <john.johansen@canonical.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Josh Triplett <josh@joshtriplett.org>,
Mateusz Guzik <mjguzik@gmail.com>,
Al Viro <viro@zeniv.linux.org.uk>,
linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org
Subject: Re: [6.8-rc1 Regression] Unable to exec apparmor_parser from virt-aa-helper
Date: Wed, 24 Jan 2024 08:35:29 -0800 [thread overview]
Message-ID: <202401240832.02940B1A@keescook> (raw)
In-Reply-To: <ZbE4qn9_h14OqADK@kevinlocke.name>
On Wed, Jan 24, 2024 at 09:19:54AM -0700, Kevin Locke wrote:
> Hello Linux developers,
>
> Using AppArmor 3.0.12 and libvirt 10.0.0 (from Debian packages) with
> Linux 6.8-rc1 (unpatched), I'm unable to start KVM domains due to
> AppArmor errors. Everything works fine on Linux 6.7. After attempting
> to start a domain, syslog contains:
>
> libvirtd[38705]: internal error: Child process (LIBVIRT_LOG_OUTPUTS=3:stderr /usr/lib/libvirt/virt-aa-helper -c -u libvirt-4fad83ef-4285-4cf5-953c-5c13d943c1fb) unexpected exit status 1: virt-aa-helper: error: apparmor_parser exited with error
> libvirtd[38705]: internal error: cannot load AppArmor profile 'libvirt-4fad83ef-4285-4cf5-953c-5c13d943c1fb'
>
> dmesg contains the additional message:
>
> audit: type=1400 audit(1706112657.438:74): apparmor="DENIED" operation="open" class="file" profile="virt-aa-helper" name="/usr/sbin/apparmor_parser" pid=6333 comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Oh, yikes. This means the LSM lost the knowledge that this open is an
_exec_, not a _read_.
I will starting looking at this. John might be able to point me in the
right direction more quickly, though.
Thanks for the report!
-Kees
>
> The libvirt-$GUID file is not created in /etc/apparmor.d/libvirt and
> apparmor_parser is not executed as far as I can tell.
>
> I've bisected the regression to 978ffcbf00d82b03b79e64b5c8249589b50e7463.
> Perhaps the change in this commit causes AppArmor to deny opening
> /usr/sbin/apparmor_parser in preparation for exec? For reference,
> /etc/apparmor.d/usr.lib.libvirt.virt-aa-helper contains:
>
> /{usr/,}sbin/apparmor_parser Ux,
>
> I'd appreciate any help debugging the issue further. Let me know if I
> should take it up with the AppArmor or libvirt developers to better
> understand the issue.
>
> Thanks,
> Kevin
--
Kees Cook
next parent reply other threads:[~2024-01-24 16:35 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <ZbE4qn9_h14OqADK@kevinlocke.name>
2024-01-24 16:35 ` Kees Cook [this message]
2024-01-24 16:46 ` [6.8-rc1 Regression] Unable to exec apparmor_parser from virt-aa-helper Linus Torvalds
2024-01-24 16:54 ` Linus Torvalds
2024-01-24 17:10 ` Linus Torvalds
2024-01-24 17:21 ` Kees Cook
2024-01-24 17:27 ` Linus Torvalds
2024-01-24 18:27 ` Linus Torvalds
2024-01-24 18:29 ` Linus Torvalds
2024-01-24 19:02 ` Kees Cook
2024-01-24 19:41 ` Linus Torvalds
2024-01-25 14:16 ` Tetsuo Handa
2024-01-25 17:17 ` Linus Torvalds
2024-01-27 7:04 ` Tetsuo Handa
2024-01-27 11:00 ` Tetsuo Handa
2024-01-27 11:23 ` Tetsuo Handa
2024-01-24 18:57 ` Kees Cook
2024-01-27 5:17 ` John Johansen
2024-01-24 17:15 ` Kees Cook
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