Until now we weren't able to add checks that would reject configuration
once accepted by the parser. This patch adds a new callback and
infrastructure to add such checks. In this patch all the places where
rejecting a now-invalid configuration wouldn't be a good idea are marked
with a new parser flag.
The directory name changed in a89f05ba8df095875f5ec8a9065a585af63a010b.
This unbreaks launching QEMU/KVM VMs with apparmor enabled. It also adds
the directory for the qemu guest-agent socket which is not known when
parsing the domain XML.
There is no need to deny writes on a readonly mount: write still
won't be accepted, even if the user remounts the folder as RW in
the guest as qemu sets the 9p mount as ro.
This deny rule was leading to problems for example with readonly /:
The qemu process had to write to a bunch of files in / like logs,
sockets, etc. This deny rule was also preventing auditing of these
denials, making it harder to debug.
So, after some movement in virt-aa-helper, I've noticed the
virt-aa-helper-test failing. I've ran gdb (it took me a while to
realize how to do that) and this showed up immediately:
Program received signal SIGSEGV, Segmentation fault.
strlen () at ../sysdeps/x86_64/strlen.S:106
106 ../sysdeps/x86_64/strlen.S: No such file or directory.
(gdb) bt
#0 strlen () at ../sysdeps/x86_64/strlen.S:106
#1 0x0000555555561a13 in array_starts_with (str=0x5555557ce910 "/tmp/tmp.6nI2Fkv0KL/1.img", arr=0x7fffffffd160, size=-1540438016) at security/virt-aa-helper.c:525
#2 0x0000555555561d49 in valid_path (path=0x5555557ce910 "/tmp/tmp.6nI2Fkv0KL/1.img", readonly=false) at security/virt-aa-helper.c:617
#3 0x0000555555562506 in vah_add_path (buf=0x7fffffffd3e0, path=0x5555557cb910 "/tmp/tmp.6nI2Fkv0KL/1.img", perms=0x555555581585 "rw", recursive=false) at security/virt-aa-helper.c:823
#4 0x0000555555562693 in vah_add_file (buf=0x7fffffffd3e0, path=0x5555557cb910 "/tmp/tmp.6nI2Fkv0KL/1.img", perms=0x555555581585 "rw") at security/virt-aa-helper.c:854
#5 0x0000555555562918 in add_file_path (disk=0x5555557d4440, path=0x5555557cb910 "/tmp/tmp.6nI2Fkv0KL/1.img", depth=0, opaque=0x7fffffffd3e0) at security/virt-aa-helper.c:931
#6 0x00007ffff78f18b1 in virDomainDiskDefForeachPath (disk=0x5555557d4440, ignoreOpenFailure=true, iter=0x5555555628a6 <add_file_path>, opaque=0x7fffffffd3e0) at conf/domain_conf.c:23286
#7 0x0000555555562b5f in get_files (ctl=0x7fffffffd670) at security/virt-aa-helper.c:982
#8 0x0000555555564100 in vahParseArgv (ctl=0x7fffffffd670, argc=5, argv=0x7fffffffd7e8) at security/virt-aa-helper.c:1277
#9 0x00005555555643d6 in main (argc=5, argv=0x7fffffffd7e8) at security/virt-aa-helper.c:1332
So I've taken look at valid_path() because it is obviously
calling array_starts_with() with malformed @size. And here's the
result: there are two variables to hold the size of three arrays
and their value is recalculated before each call of
array_starts_with(). What if we just use three variables,
initialize them and do not touch them afterwards?
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is a cryptographically signed message in MIME format.
Some UEFI firmwares may want to use a non-volatile memory to store some
variables.
If AppArmor is enabled, and NVRAM store file is set currently
virt-aa-helper does
not add the NVRAM store file to the template. Add this file for
read/write when
this functionality is defined in domain XML.
Signed-off-by: Peter Kieser <peter@kieser.ca>
We forbid access to /usr/share/, but (at least on Debian-based systems)
the Open Virtual Machine Firmware files needed for booting UEFI virtual
machines in QEMU live in /usr/share/ovmf/. Therefore, we need to add
that directory to the list of read only paths.
A similar patch was suggested by Jamie Strandboge <jamie@canonical.com>
on https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1483071.
First check overrides, then read only files then restricted access
itself.
This allows us to mark files for read only access whose parents were
already restricted for read write.
Based on a proposal by Martin Kletzander
With commit 3f9868a virt-aa-helper stopped working due to missing
DomainGuest in the caps.
The test with -c without arch also needs to be
removed since the new capabilities code uses the host arch when none is
provided.
Initializing libvirt log in virt-aa-helper and getting it to output
libvirt log to stderr. This will help debugging problems happening in
libvirt functions called from within virt-aa-helper
Commit 03d7462d added it for channels, but it is also needed for serials. Add
it for serials, parallels, and consoles as well.
This solves https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1015154
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
QEMU working in vhost-user mode communicates with the other end (i.e.
some virtual router application) via unix domain sockets. This requires
that permissions for the socket files are correctly written into
/etc/apparmor.d/libvirt/libvirt-UUID.files.
Signed-off-by: Michal Dubiel <md@semihalf.com>
This needs to specified in way too many places for a simple validation
check. The ostype/arch/virttype validation checks later in
DomainDefParseXML should catch most of the cases that this was covering.
The virDomainDefParse* and virDomainDefFormat* methods both
accept the VIR_DOMAIN_XML_* flags defined in the public API,
along with a set of other VIR_DOMAIN_XML_INTERNAL_* flags
defined in domain_conf.c.
This is seriously confusing & error prone for a number of
reasons:
- VIR_DOMAIN_XML_SECURE, VIR_DOMAIN_XML_MIGRATABLE and
VIR_DOMAIN_XML_UPDATE_CPU are only relevant for the
formatting operation
- Some of the VIR_DOMAIN_XML_INTERNAL_* flags only apply
to parse or to format, but not both.
This patch cleanly separates out the flags. There are two
distint VIR_DOMAIN_DEF_PARSE_* and VIR_DOMAIN_DEF_FORMAT_*
flags that are used by the corresponding methods. The
VIR_DOMAIN_XML_* flags received via public API calls must
be converted to the VIR_DOMAIN_DEF_FORMAT_* flags where
needed.
The various calls to virDomainDefParse which hardcoded the
use of the VIR_DOMAIN_XML_INACTIVE flag change to use the
VIR_DOMAIN_DEF_PARSE_INACTIVE flag.
Commit 'c264eeaa' didn't do the prerequisite 'make syntax-check' before
pushing. There was a <tab> in the whitespace for the comment. Replaced
with spaces and aligned.
pushed as build breaker since Jenkins complained loudly
Rule sc_prohibit_newline_at_end_of_diagnostic for syntax-check does
check for passing strings ending with '\n' two lines after known
functions. This is, of course subject to false positives, so for the
sake of future changes, trick that syntax-check by adding one more line
with a comment.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Add a new parameter to virStorageFileGetMetadata that will break the
backing chain detection process and report useful error message rather
than having to use virStorageFileChainGetBroken.
This patch just introduces the option, usage will be provided
separately.
Up to now, users can configure BIOS via the <loader/> element. With
the upcoming implementation of UEFI this is not enough as BIOS and
UEFI are conceptually different. For instance, while BIOS is ROM, UEFI
is programmable flash (although all writes to code section are
denied). Therefore we need new attribute @type which will
differentiate the two. Then, new attribute @readonly is introduced to
reflect the fact that some images are RO.
Moreover, the OVMF (which is going to be used mostly), works in two
modes:
1) Code and UEFI variable store is mixed in one file.
2) Code and UEFI variable store is separated in two files
The latter has advantage of updating the UEFI code without losing the
configuration. However, in order to represent the latter case we need
yet another XML element: <nvram/>. Currently, it has no additional
attributes, it's just a bare element containing path to the variable
store file.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Rework the apparmor lxc profile abstraction to mimic ubuntu's container-default.
This profile allows quite a lot, but strives to restrict access to
dangerous resources.
Removing the explicit authorizations to bash, systemd and cron files,
forces them to keep the lxc profile for all applications inside the
container. PUx permissions where leading to running systemd (and others
tasks) unconfined.
Put the generic files, network and capabilities restrictions directly
in the TEMPLATE.lxc: this way, users can restrict them on a per
container basis.
Don't fail when there is nothing to do, as a tweak to the previous
patch regarding output of libvirt-UUID.files for LXC apparmor profiles
Signed-off-by: Eric Blake <eblake@redhat.com>
In the future we might need to track state of individual images. Move
the readonly and shared flags to the virStorageSource struct so that we
can keep them in a per-image basis.
As part of the work on backing chains, I'm finding that it would
be easier to directly manipulate chains of pointers (adding a
snapshot merely adjusts pointers to form the correct list) rather
than copy data from one struct to another. This patch converts
domain disk source to be a pointer.
In this patch, the pointer is ALWAYS allocated (thanks in part to
the previous patch forwarding all disk def allocation through a
common point), and all other changse are just mechanical fallout of
the new type; there should be no functional change. It is possible
that we may want to leave the pointer NULL for a cdrom with no
medium in a later patch, but as that requires a closer audit of the
source to ensure we don't fault on a null dereference, I didn't do
it here.
* src/conf/domain_conf.h (_virDomainDiskDef): Change type of src.
* src/conf/domain_conf.c: Adjust all clients.
* src/security/security_selinux.c: Likewise.
* src/qemu/qemu_domain.c: Likewise.
* src/qemu/qemu_command.c: Likewise.
* src/qemu/qemu_conf.c: Likewise.
* src/qemu/qemu_process.c: Likewise.
* src/qemu/qemu_migration.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/lxc/lxc_driver.c: Likewise.
* src/lxc/lxc_controller.c: Likewise.
* tests/securityselinuxlabeltest.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
My future work will modify the metadata crawler function to use the
storage driver file APIs to access the files instead of accessing them
directly so that we will be able to request the metadata for remote
files too. To avoid linking the storage driver to every helper file
using the utils code, the backing chain traversal function needs to be
moved to the storage driver source.
Additionally the virt-aa-helper and virstoragetest programs need to be
linked with the storage driver as a result of this change.
To avoid having the root of a backing chain present twice in the list we
need to invert the working of virStorageFileGetMetadataRecurse.
Until now the recursive worker created a new backing chain element from
the name and other information passed as arguments. This required us to
pass the data of the parent in a deconstructed way and the worker
created a new entry for the parent.
This patch converts this function so that it just fills in metadata
about the parent and creates a backing chain element from those. This
removes the duplication of the first element.
To avoid breaking the test suite, virstoragetest now calls a wrapper
that creates the parent structure explicitly and pre-fills it with the
test data with same function signature as previously used.
Switch over to storing of the backing chain as a recursive
virStorageSource structure.
This is a string based move. Currently the first element will be present
twice in the backing chain as currently the retrieval function stores
the parent in the newly detected chain. This will be fixed later.
Since it is an abbreviation, PCI should always be fully
capitalized or full lower case, never Pci.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
I noticed that the apparmor code could request metadata even
for a cdrom with no media, which would cause a memory leak of
the hash table used to look for loops in the backing chain.
But even before that, we blindly dereferenced the path for
printing a debug statement, so it is just better to enforce
that this is only used on non-NULL names.
* src/util/virstoragefile.c (virStorageFileGetMetadata): Assume
non-NULL path.
* src/util/virstoragefile.h: Annotate this.
* src/security/virt-aa-helper.c (get_files): Fix caller.
Signed-off-by: Eric Blake <eblake@redhat.com>
See lp#1276719 for the bug description. As virt-aa-helper doesn't know
the VFIO groups to use for the guest, allow access to all
/dev/vfio/[0-9]* and /dev/vfio/vfio files if there is a potential need
for vfio
Signed-off-by: Eric Blake <eblake@redhat.com>
