Re: [libvirt] [PATCH] apparmor: allow qemu abstraction to read /proc/pid/cmdline

On Thu, 2017-11-30 at 10:43 -0700, Jim Fehlig wrote: > Noticed the following denial in audit.log when shutting down > an apparmor confined domain > > type=AVC msg=audit(1512002299.742:131): apparmor="DENIED" > operation="open" profile="libvirt-66154842-e926-4f92-92f0- > 1c1bf61dd1ff" > name="/proc/1475/cmdline" pid=2958 comm="qemu-system-x86" > requested_mask="r" denied_mask="r" fsuid=469 ouid=0 > > Squelch the denial by allowing read access to /proc/<pid>/cmdline. > > Signed-off-by: Jim Fehlig <jfehlig(a)suse.com&gt; > --- > > Note: In the audit.log snippet, PID 1475 is libvirtd and 2958 is the > qemu process. I must admit it is not clear to me why > /proc/<libvirtd-pid>/cmdline is read on domain shutdown. > > examples/apparmor/libvirt-qemu | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/examples/apparmor/libvirt-qemu > b/examples/apparmor/libvirt-qemu > index 73bdbae87..3d9eed9ec 100644 > --- a/examples/apparmor/libvirt-qemu > +++ b/examples/apparmor/libvirt-qemu > @@ -25,6 +25,7 @@ > /dev/ptmx rw, > /dev/kqemu rw, > @{PROC}/*/status r, > + @{PROC}/@{pid}/cmdline r, Note this is an information leak and allows reading potentially sensitive information, such as passwords given on the command line. Eg: $ cat /proc/13335/cmdline | tr '\0' ' ' sh /tmp/testme --password=sensitive

Would it be possible to use 'owner' match? Eg: owner @{PROC}/@{pid}/cmdline r,