Commit Graph

882 Commits

Author SHA1 Message Date
Peng Liang
32b11c49e6 security: Remove unused includes
Signed-off-by: Peng Liang <tcx4c70@gmail.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-06-07 16:07:00 +02:00
Ján Tomko
9e41a59ce5 apparmor: report error when removing profile failed
Assign the return value to 'rc' before comparing it.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2022-05-25 15:10:02 +02:00
Andrea Bolognani
2b98d5d91d apparmor: Allow locking AAVMF firmware
We already allow this for OVMF.

Closes: https://gitlab.com/libvirt/libvirt/-/issues/312
Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2022-05-23 14:01:21 +02:00
Max Goodhart
42cb548045
Allow VM to read sysfs PCI config, revision files
This fixes a blank screen when viewing a VM with virtio graphics and
gl-accelerated Spice display on Ubuntu 22.04 / libvirt 8.0.0 / qemu 6.2.

Without these AppArmor permissions, the libvirt error log contains
repetitions of:

qemu_spice_gl_scanout_texture: failed to get fd for texture

This appears to be similar to this GNOME Boxes issue:
https://gitlab.gnome.org/GNOME/gnome-boxes/-/issues/586

Fixes: https://launchpad.net/bugs/1972075

Signed-off-by: Max Goodhart <c@chromakode.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
2022-05-20 07:37:14 +02:00
Martin Kletzander
b7b8cd6ad6 apparmor: Add support for dbus chardev
Commit 7648e40da5 added support for dbus chardev but forgot to handle it in
AppArmor code.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2022-05-19 14:15:02 +02:00
Marc-André Lureau
7648e40da5 conf: add <serial type='dbus'>
Like a Spice port, a dbus serial must specify an associated channel name.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2022-05-19 12:36:35 +02:00
Jonathon Jongsma
05b09f039e conf: add qemu-vdagent channel
Add the ability to configure a qemu-vdagent in guest domains. This
device is similar to the spice vdagent channel except that qemu handles
the spice-vdagent protocol messages itself rather than routing them over
a spice protocol channel.

The qemu-vdagent device has two notable configuration options which
determine whether qemu will handle particular vdagent features:
'clipboard' and 'mouse'.

The 'clipboard' option allows qemu to synchronize its internal clipboard
manager with the guest clipboard, which enables client<->guest clipboard
synchronization for non-spice guests such as vnc.

The 'mouse' option allows absolute mouse positioning to be sent over the
vdagent channel rather than using a usb or virtio tablet device.

Sample configuration:
  <channel type='qemu-vdagent'>
    <target type='virtio' name='com.redhat.spice.0'/>
    <source>
      <clipboard copypaste='yes'/>
      <mouse mode='client'/>
    </source>
  </channel>

Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2022-05-10 11:00:15 -05:00
Lena Voytek
d97f8807d2 apparmor: Allow swtpm to use its own apparmor profile
Signed-off-by: Lena Voytek <lena.voytek@canonical.com>
2022-04-20 11:55:21 +00:00
Tim Wiederhake
c8f5b33631 security_manager: Use automatic mutex management
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2022-04-14 19:03:43 +02:00
Andrea Bolognani
b94239a61e meson: Use dicts to initialize cfg_data objects
Instead of creating an empty object and then setting keys one
at a time, it is possible to pass a dict object to
configuration_data(). This is nicer because it doesn't require
repeating the name of the cfg_data object over and over.

There is one exception: the 'conf' object, where we store values
that are used directly by C code. In that case, using a dict
object is not feasible for two reasons: first of all, replacing
the set_quoted() calls would result in awkward code with a lot
of calls to format(); moreover, since code that modifies it is
sprinkled all over the place, refactoring it would probably
make things more complicated rather than simpler.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2022-04-01 15:33:19 +02:00
Martin Pitt
7aec69b7fb
apparmor: Fix QEMU access for UEFI variable files
QEMU needs to read, write, and lock the NVRAM *.fd files with UEFI
firmware.

Fixes: https://bugs.debian.org/1006324
Fixes: https://launchpad.net/bugs/1962035

Signed-off-by: Martin Pitt <mpitt@debian.org>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
2022-03-09 10:50:23 +01:00
Martin Kletzander
fad2bff51e Include sys/wait.h instead of wait.h
That is the proper POSIX way.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-03-07 10:31:22 +01:00
Michal Privoznik
87a43a907f lib: Use g_clear_pointer() more
This change was generated using the following spatch:

  @ rule1 @
  expression a;
  identifier f;
  @@
    <...
  - f(*a);
    ... when != a;
  - *a = NULL;
  + g_clear_pointer(a, f);
    ...>

  @ rule2 @
  expression a;
  identifier f;
  @@
    <...
  - f(a);
    ... when != a;
  - a = NULL;
  + g_clear_pointer(&a, f);
    ...>

Then, I left some of the changes out, like tools/nss/ (which
doesn't link with glib) and put back a comment in
qemuBlockJobProcessEventCompletedActiveCommit() which coccinelle
decided to remove (I have no idea why).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-02-08 08:42:07 +01:00
Michal Privoznik
bdb95b520c conf: Convert virDomainHostdevDefParseXMLSubsys() to virXMLProp*()
After previous cleanups, the virDomainHostdevDefParseXMLSubsys()
function uses a mixture of virXMLProp*() and the old
virXMLPropString() + virXXXTypeFromString() patterns. Rework it
so that virXMLProp*() is used.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2022-01-21 16:42:14 +01:00
Martin Kletzander
9f6749dea0 util: Check for errors in virLogSetFromEnv
And make callers check the return value as well.  This helps error out early for
invalid environment variables.

That is desirable because it could lead to deadlocks.  This can happen when
resetting logging after fork() reports translated errors because gettext
functions are not reentrant.  Well, it is not limited to resetting logging after
fork(), it can be any translation at that phase, but parsing environment
variables is easy to make fail on purpose to show the result, it can also happen
just due to a typo.

Before this commit it is possible to deadlock the daemon on startup
with something like:

LIBVIRT_LOG_FILTERS='1:*' LIBVIRT_LOG_OUTPUTS=1:stdout libvirtd

where filters are used to enable more logging and hence make the race less rare
and outputs are set to invalid

Combined with the previous patches this changes
the following from:

...
<deadlock>

to:

...
libvirtd: initialisation failed

The error message is improved in future commits and is also possible thanks to
this patch.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Erik Skultety <eskultet@redhat.com>
2022-01-05 14:08:40 +01:00
Ján Tomko
eff68d3637 security: apparmor: use automatic cleanup in load_profile
Use g_auto for virCommand and char * and drop the cleanup label.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-12-13 18:20:46 +01:00
Peter Krempa
690efb960f Switch away from virHashFree
Use 'g_clear_pointer(&ptr, g_hash_table_unref)' instead.

In few instances it allows us to also remove explicit clearing of
pointers.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2021-12-01 13:53:12 +01:00
Peter Krempa
f7ff8556ad virSecurityLabelDef: Declare 'type' as 'virDomainSeclabelType'
Use the appropriate enum type instead of an int and fix the XML parser
and one missing fully populated switch.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-24 09:20:38 +01:00
Peter Krempa
42b0000699 conf: Properly instantiate virDomainChrSourceDef in virDomainTPMDef
'virDomainChrSourceDef' contains private data so 'virDomainChrSourceDefNew'
must be used to allocate it. 'virDomainTPMDef' was using it directly
which won't work with the chardev helper functions.

Convert it to a pointer to properly allocate private data.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-19 12:38:35 +01:00
Peter Krempa
3c558f56f8 conf: Convert 'chr' in virDomainShmemDef to proper pointer
The main reason is to ensure that the private data are properly
allocated for every instance.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-19 12:38:34 +01:00
Ioanna Alifieraki
4ab33415db
virt-aa-helper: Purge profile if corrupted
This commit aims to address the bug reported in [1] and [2].
If the profile is corrupted (0-size) the VM cannot be launched.
To overcome this, check if the profile exists and if it has 0 size
remove it.

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=890084
[2] https://bugs.launchpad.net/bugs/1927519

Signed-off-by: Ioanna Alifieraki <ioanna-maria.alifieraki@canonical.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-04 13:07:19 +01:00
Michal Privoznik
2996a94dd0 lib: Don't check for virCapabilitiesAddGuestDomain() retval
The virCapabilitiesAddGuestDomain() function can't fail. It
aborts on OOM. Therefore, there's no need to check for its
return value.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:08:26 +01:00
Michal Privoznik
c18d9e23fa lib: Don't check for virCapabilitiesAddGuest() retval
The virCapabilitiesAddGuest() function can't fail. It aborts on
OOM. Therefore, there's no need to check for its return value.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-11-01 16:05:52 +01:00
Michal Privoznik
857df2fe50 lib: Drop intermediary return variables
In a few places we declare a variable (which is optionally
followed by a code not touching it) then set the variable to a
value and return the variable immediately. It's obvious that the
variable is needless and the value can be returned directly
instead.

This patch was generated using this semantic patch:

  @@
  type T;
  identifier ret;
  expression E;
  @@
  - T ret;
  ... when != ret
      when strict
  - ret = E;
  - return ret;
  + return E;

After that I fixed couple of formatting issues because coccinelle
formatted some lines differently than our coding style.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-10-25 12:48:46 +02:00
Peter Krempa
43d48eebf9 virDomainSmartcardDef: Declare 'type' as virDomainSmartcardType
Use 'virXMLPropEnum' to parse it and fix all switch statements which
didn't include the VIR_DOMAIN_SMARTCARD_TYPE_LAST case.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-10-12 20:54:53 +02:00
Christian Ehrhardt
e3c5a8ec73
apparmor: ceph config file names
If running multiple [1] clusters (uncommon) the ceph config file will be
derived from the cluster name. Therefore the rule to allow to read ceph
config files need to be opened up slightly to allow for that condition.

[1]: https://docs.ceph.com/en/mimic/rados/configuration/common/#running-multiple-clusters

Fixes: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1588576

Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-10-11 08:01:27 +02:00
Michal Privoznik
f931cb7f21 conf: Introduce virtio-mem <memory/> model
The virtio-mem is paravirtualized mechanism of adding/removing
memory to/from a VM. A virtio-mem-pci device is split into blocks
of equal size which are then exposed (all or only a requested
portion of them) to the guest kernel to use as regular memory.
Therefore, the device has two important attributes:

  1) block-size, which defines the size of a block
  2) requested-size, which defines how much memory (in bytes)
     is the device requested to expose to the guest.

The 'block-size' is configured on command line and immutable
throughout device's lifetime. The 'requested-size' can be set on
the command line too, but also is adjustable via monitor. In
fact, that is how management software places its requests to
change the memory allocation. If it wants to give more memory to
the guest it changes 'requested-size' to a bigger value, and if it
wants to shrink guest memory it changes the 'requested-size' to a
smaller value. Note, value of zero means that guest should
release all memory offered by the device. Of course, guest has to
cooperate. Therefore, there is a third attribute 'size' which is
read only and reflects how much memory the guest still has. This
can be different to 'requested-size', obviously. Because of name
clash, I've named it 'current' and it is dealt with in future
commits (it is a runtime information anyway).

In the backend, memory for virtio-mem is backed by usual objects:
memory-backend-{ram,file,memfd} and their size puts the cap on
the amount of memory that a virtio-mem device can offer to a
guest. But we are already able to express this info using <size/>
under <target/>.

Therefore, we need only two more elements to cover 'block-size'
and 'requested-size' attributes. This is the XML I've came up
with:

  <memory model='virtio-mem'>
    <source>
      <nodemask>1-3</nodemask>
      <pagesize unit='KiB'>2048</pagesize>
    </source>
    <target>
      <size unit='KiB'>2097152</size>
      <node>0</node>
      <block unit='KiB'>2048</block>
      <requested unit='KiB'>1048576</requested>
    </target>
    <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
  </memory>

I hope by now it is obvious that:

  1) 'requested-size' must be an integer multiple of
     'block-size', and
  2) virtio-mem-pci device goes onto PCI bus and thus needs PCI
     address.

Then there is a limitation that the minimal 'block-size' is
transparent huge page size (I'll leave this without explanation).

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-10-01 11:02:53 +02:00
Jim Fehlig
2e8ebfe3fa qemu: Set label on vhostuser net device when hotplugging
Attaching a newly created vhostuser port to a VM fails due to an
apparmor denial

internal error: unable to execute QEMU command 'chardev-add': Failed
to bind socket to /run/openvswitch/vhu838c4d29-c9: Permission denied

In the case of a net device type VIR_DOMAIN_NET_TYPE_VHOSTUSER, the
underlying chardev is not labeled in qemuDomainAttachNetDevice prior
to calling qemuMonitorAttachCharDev.

A simple fix would be to call qemuSecuritySetChardevLabel using the
embedded virDomainChrSourceDef in the virDomainNetDef vhostuser data,
but this incurs the risk of incorrectly restoring the label. E.g.
consider the DAC driver behavior with a vhostuser net device, which
uses a socket for the chardev backend. The DAC driver uses XATTRS to
store original labelling information, but XATTRS are not compatible
with sockets. Without the original labelling information, the socket
labels will be restored with root ownership, preventing other
less-privileged processes from connecting to the socket.

This patch avoids overloading chardev labelling with vhostuser net
devices by introducing virSecurityManager{Set,Restore}NetdevLabel,
which is currently only implemented for the apparmor driver. The
new APIs are then used to set and restore labels for the vhostuser
net devices.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-08-26 16:06:45 -06:00
Ján Tomko
5590fbf8d6 Remove redundant labels
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-08-17 18:27:13 +02:00
Ján Tomko
2c426d2e30 Use g_auto for xmlFreeDoc everywhere
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-08-17 18:27:13 +02:00
Ján Tomko
5dae71ee8c Use g_auto for xmlXPathContext everywhere
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-08-17 18:27:13 +02:00
Zhenyu Ye
f14d6ab537 security: fix use-after-free in virSecuritySELinuxReserveLabel
commit 2e668a61d5ae4("Fix error handling when adding MCS labels") uses
the 'pctx' in virReportError after it has been freed. Fix it.

Fixes: 2e668a61d5
Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
2021-08-17 12:07:36 +02:00
Andrea Bolognani
2c0f47e75c meson: Always use the / operator to join paths
This is the preferred way to do it, but there were a few
instances in which some of the path components had embedded
slashes instead.

Signed-off-by: Andrea Bolognani <abologna@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2021-08-11 09:16:36 +02:00
Peter Krempa
4e7576a741 virSecuritySELinuxContextListAppend: Remove unreachable cleanup
'item' is always NULLed-out by VIR_APPEND_ELEMENT and 'ret' variable is
always 0 when used so both can be removed.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-08-06 08:53:26 +02:00
Peter Krempa
98f6f2081d util: alloc: Reimplement VIR_APPEND_ELEMENT using virAppendElement
Use virAppendElement instead of virInsertElementsN to implement
VIR_APPEND_ELEMENT which allows us to remove error handling as the
only relevant errors were removed when switching to aborting memory
allocation functions.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-08-06 08:53:25 +02:00
Tim Wiederhake
cc69362e36 virSecuritySELinuxQEMUInitialize: virHashNew cannot return NULL
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-07-23 11:32:12 +02:00
Tim Wiederhake
50b068d239 virSecuritySELinuxLXCInitialize: virHashNew cannot return NULL
Signed-off-by: Tim Wiederhake <twiederh@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
2021-07-23 11:32:12 +02:00
Boris Fiuczynski
96bc8312aa conf: Refactor launch security to allow more types
Adding virDomainSecDef for general launch security data
and moving virDomainSEVDef as an element for SEV data.

Signed-off-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Pavel Hrdina <phrdina@redhat.com>
2021-07-21 13:30:14 +02:00
Jim Fehlig
3c18bc304e Apparmor: Add profile for virtxend
A new apparmor profile initially derived from the libvirtd profile.
All rules were prefixed with the 'audit' qualifier to verify they
are actually used by virtxend. It turns out that several, beyond
the obvious ones, can be dropped in the resulting virtxend profile.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
2021-07-14 09:16:58 -06:00
Jim Fehlig
ccba72b414 Apparmor: Add profile for virtqemud
A new apparmor profile derived from the libvirtd profile, with non-QEMU
related rules removed. Adopt the libvirt-qemu abstraction to work with
the new profile.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
2021-07-14 09:16:58 -06:00
Olaf Hering
75803d16ee apparmor: Allow /usr/libexec for private xen-tools binaries
This is a followup for commit e906c4d02b
("apparmor: Allow /usr/libexec for libxl-save-helper and pygrub"):

In recent rpm versions --libexecdir changed from /usr/lib64 to
/usr/libexec. A plain rpmbuild %configure in xen.git will install all
files, including the private copies of qemu, into /usr/libexec/xen/bin.
Expand the existing pattern to cover also this libexecdir variant.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-07-14 17:07:22 +02:00
Stefan Berger
1c78675c6c virt-aa-helper: Allow swtpm to fsync on dir
Allow swtpm (0.7.0 or later) to fsync on the directory where it writes
its state files into so that "the entry in the directory containing the
file has also reached disk" (fsync(2)).

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Neal Gompa <ngompa13@gmail.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
2021-07-14 13:29:59 +02:00
Daniel P. Berrangé
15073504db security: fix SELinux label generation logic
A process can access a file if the set of MCS categories
for the file is equal-to *or* a subset-of, the set of
MCS categories for the process.

If there are two VMs:

  a) svirt_t:s0:c117
  b) svirt_t:s0:c117,c720

Then VM (b) is able to access files labelled for VM (a).

IOW, we must discard case where the categories are equal
because that is a subset of many other valid category pairs.

Fixes: https://gitlab.com/libvirt/libvirt/-/issues/153
CVE-2021-3631
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2021-06-30 14:51:42 +01:00
Jim Fehlig
64ae7635e6 Apparmor: Allow reading /etc/ssl/openssl.cnf
I noticed the following denial when running confined VMs with the QEMU
driver

type=AVC msg=audit(1623865089.263:865): apparmor="DENIED" operation="open" \
profile="virt-aa-helper" name="/etc/ssl/openssl.cnf" pid=12503 \
comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0

Allow reading the file by including the openssl abstraction in the
virt-aa-helper profile.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
2021-06-24 13:54:47 -06:00
Jim Fehlig
f552e68d9f Apparmor: Allow reading libnl's classid file
I noticed the following denial messages from apparmor in audit.log when
starting confined VMs via the QEMU driver

type=AVC msg=audit(1623864006.370:837): apparmor="DENIED" operation="open" \
profile="virt-aa-helper" name="/etc/libnl/classid" pid=11265 \
comm="virt-aa-helper" requested_mask="r" denied_mask="r" fsuid=0 ouid=0

type=AVC msg=audit(1623864006.582:849): apparmor="DENIED" operation="open" \
profile="libvirt-0ca2720d-6cff-48bb-86c2-61ab9a79b6e9" \
name="/etc/libnl/classid" pid=11270 comm="qemu-system-x86" \
requested_mask="r" denied_mask="r" fsuid=107 ouid=0

It is possible for site admins to assign names to classids in this file,
which are then used by all libnl tools, possibly those used by libvirt.
To be on the safe side, allow read access to the file in the virt-aa-helper
profile and the libvirt-qemu abstraction.

Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
2021-06-24 13:54:42 -06:00
Michal Privoznik
70a2b618bb qemu: Deduplicate code in qemuSecurityChownCallback()
The DAC security driver has an option to register a callback that
is called instead of chown(). So far QEMU is the only user of
this feature and it's used to set labels on non-local disks (like
gluster), where exists notion of owners but regular chown() can't
be used.

However, this callback (if set) is called always, even for local
disks. And thus the QEMU's implementation duplicated parts of the
DAC driver to deal with chown().

If the DAC driver would call the callback only for non-local
disks then the QEMU's callback can be shorter.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-06-17 15:49:17 +02:00
Michal Privoznik
6fba030fed virSecurityDACSetOwnershipInternal: Fix WIN32 code
I must admit, I have no idea why we build such POSIX dependent
code as DAC driver for something such not POSIX as WIN32. Anyway,
the code which is supposed to set error is not doing that. The
proper way is to mimic what chown() does:

  On error, -1 is returned, and errno is set to indicate the error.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-06-17 15:49:12 +02:00
Michal Privoznik
b332c2cf89 virSecurityDACSetOwnershipInternal: Don't overwrite @path argument
As shown in the previous commit, @path can be NULL. However, in
that case @src->path is also NULL. Therefore, trying to "fix"
@path to be not NULL is not going to succeed. The real value of
NULLSTR() is in providing a non-NULL string for error reporting.
Well, that can be done in the error reporting without overwriting
argument.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-06-17 15:49:07 +02:00
Michal Privoznik
5cfb3369b1 virSecurityDACSetOwnershipInternal: Drop dead code
The virSecurityDACSetOwnershipInternal() function accepts two
arguments (among others): @path and @src. The idea being that in
some cases @path is NULL and @src is not and then @path is filled
from @src->path. However, this is done in both callers already
(because of seclabel remembering/recall). Therefore, this code in
virSecurityDACSetOwnershipInternal() is dead, effectively.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-06-17 15:49:02 +02:00
Michal Privoznik
4ac78b95d3 security_dac: Don't check for !priv in virSecurityDACSetOwnershipInternal()
The virSecurityDACSetOwnershipInternal() has two callers and in
both the private data (@priv) is obtained via
virSecurityManagerGetPrivateData(). But in case of DAC driver the
private data can never be NULL. This is because the private data
is allocated in virSecurityManagerNewDriver() according to
.privateDataLen attribute of secdriver. In case of DAC driver the
attribute is set to sizeof(virSecurityDACData).

NB, no other function within DAC driver checks for !priv.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
2021-06-17 15:48:56 +02:00