Re: [libvirt] [PATCH V3] apparmor: support ptrace checks
Hi Jim,
On Fri, Sep 22, 2017 at 05:02:42PM -0600, Jim Fehlig wrote:
Kernel 4.13 introduced finer-grained ptrace checks
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/c...
With kernel 4.13 and apparmor 2.11, simply starting libvirtd
results in the following apparmor denial
type=AVC msg=audit(1506112085.645:954): apparmor="DENIED"
operation="ptrace" profile="/usr/sbin/libvirtd" pid=6984
comm="libvirtd" requested_mask="trace" denied_mask="trace"
peer="unconfined"
Attempting to start an unconfined domain results in
type=AVC msg=audit(1506112301.227:1112): apparmor="DENIED"
operation="ptrace" profile="/usr/sbin/libvirtd" pid=7498
comm="libvirtd" requested_mask="trace" denied_mask="trace"
peer="/usr/sbin/libvirtd"
And attempting to start a confined domain results in
type=AVC msg=audit(1506112631.408:1312): apparmor="DENIED"
operation="open" profile="virt-aa-helper"
name="/etc/libnl/classid"
pid=8283 comm="virt-aa-helper" requested_mask="r"
denied_mask="r"
fsuid=0 ouid=0
type=AVC msg=audit(1506112631.530:1319): apparmor="DENIED"
operation="open" profile="virt-aa-helper"
name="/etc/libnl/classid"
pid=8289 comm="virt-aa-helper" requested_mask="r"
denied_mask="r"
fsuid=0 ouid=0
type=AVC msg=audit(1506112632.186:1324): apparmor="DENIED"
operation="ptrace" profile="/usr/sbin/libvirtd" pid=8342
comm="libvirtd" requested_mask="trace" denied_mask="trace"
peer="libvirt-66154842-e926-4f92-92f0-1c1bf61dd1ff"
Add ptrace rules to allow the trace operations.
Resolves: https://bugzilla.suse.com/show_bug.cgi?id=1058847
Signed-off-by: Jim Fehlig <jfehlig(a)suse.com>
---
V3:
fix ptrace rule for per-domain profiles
V2:
restrict ptrace permissions
drop support for dbus, signal, and unix
examples/apparmor/usr.sbin.libvirtd | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/examples/apparmor/usr.sbin.libvirtd b/examples/apparmor/usr.sbin.libvirtd
index acb59e071..fa4ebb355 100644
--- a/examples/apparmor/usr.sbin.libvirtd
+++ b/examples/apparmor/usr.sbin.libvirtd
@@ -37,6 +37,10 @@
network packet dgram,
network packet raw,
+ ptrace (trace) peer=unconfined,
+ ptrace (trace) peer=/usr/sbin/libvirtd,
+ ptrace (trace) peer=libvirt-*,
+
This works here too! And I can even drop the first rule (ptrace (trace)
peer=unconfined) and things still work (and from reading the profile and
Jamies explanations it should work without it). Can you check if that
works for you too? Otherwise:
Reviewed-By: Guido Günther <agx(a)sigxcpu.org>
# Very lenient profile for libvirtd since we want to first focus
on confining
# the guests. Guests will have a very restricted profile.
/ r,
--
2.14.1