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.
Many of the functions follow the pattern:
virSecurity.*Security.*Label
Remove the second 'Security' from the names, it should be
obvious that the virSecurity* functions deal with security
labels even without it.
Many of the functions follow the pattern:
virSecurity.*Security.*Label
Remove the second 'Security' from the names, it should be obvious
that the virSecurity* functions deal with security labels even
without it.
Many of the functions follow the pattern:
virSecurity.*Security.*Label
Remove the second 'Security' from the names, it should be obvious
that the virSecurity* functions deal with security labels even
without it.
Fixes several style issues and removes "DEF" (what is it supposed to
mean anyway?) from debug messages.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
We have macros for both positive and negative string matching.
Therefore there is no need to use !STREQ or !STRNEQ. At the same
time as we are dropping this, new syntax-check rule is
introduced to make sure we won't introduce it again.
Signed-off-by: Ishmanpreet Kaur Khera <khera.ishman@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Even though the APIs are not implemented yet, they create a
skeleton that can be filled in later.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This function should really be called only when we want to change
ownership of a file (or disk source). Lets switch to calling a
wrapper function which will eventually record the current owner
of the file and call virSecurityDACSetOwnershipInternal
subsequently.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is pure code adjustment. The structure is going to be needed
later as it will hold a reference that will be used to talk to
virtlockd. However, so far this is no functional change just code
preparation.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This is pure code adjustment. The structure is going to be needed
later as it will hold a reference that will be used to talk to
virtlockd. However, so far this is no functional change just code
preparation.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
It's better if we stat() file that we are about to chown() at
first and check if there's something we need to change. Not that
it would make much difference, but for the upcoming patches we
need to be doing stat() anyway. Moreover, if we do things this
way, we can drop @chown_errno variable which will become
redundant.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Correctly mark the places where we need to remember and recall
file ownership. We don't want to mislead any potential developer.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
So imagine you want to crate new security manager:
if (!(mgr = virSecurityManagerNew("selinux", "QEMU", false, true, false, true)));
Hard to parse, right? What about this:
if (!(mgr = virSecurityManagerNew("selinux", "QEMU",
VIR_SECURITY_MANAGER_DEFAULT_CONFINED |
VIR_SECURITY_MANAGER_PRIVILEGED)));
Now that's better! This is what the commit does.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
profile_status function was not making any difference between error
cases and unconfined profiles. The problem with this approach is that
dominfo was throwing an error on unconfined domains.
https://bugzilla.redhat.com/show_bug.cgi?id=1124841
If running in session mode it may happen that we fail to set
correct SELinux label, but the image may still be readable to
the qemu process. Take this into account.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We may want to do some decisions in drivers based on fact if we
are running as privileged user or not. Propagate this info there.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
We have plenty of callbacks in the driver. Some of these
callbacks require more than one argument to be passed. For that
we currently have a data type (struct) per each callback. Well,
so far for only one - SELinuxSCSICallbackData. But lets turn it
into more general name so it can be reused in other callbacks too
instead of each one introducing a new, duplicate data type.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
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>
Remove unused variable, tag unused parameter and adjust return type.
introduced by 3f48345f7e
CC security/libvirt_security_manager_la-security_selinux.lo
security/security_selinux.c: In function 'virSecuritySELinuxDomainSetDirLabel':
security/security_selinux.c:2520:5: error: return makes pointer from integer without a cast [-Werror]
security/security_selinux.c:2514:9: error: unused variable 'ret' [-Werror=unused-variable]
security/security_selinux.c:2509:59: error: unused parameter 'mgr' [-Werror=unused-parameter]
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
SELinux security driver already does that, but DAC driver somehow missed
the memo. Let's fix it so it works the same way.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
In virSecuritySELinuxSetSecurityChardevLabel() we are labelling unix
socket path, but accessing another structure of the union. This does
not pose a problem currently as both paths are at the same offset, but
this should be fixed for the future.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
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
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.
if (mgr == NULL || mgr->drv == NULL)
return ret;
This check isn't really necessary, security manager cannot be a NULL
pointer as it is either selinux (by default) or 'none', if no other driver is
set in the config. Even with no config file driver name yields 'none'.
The other hunk checks for domain's security model validity, but we should
also check devices' security model as well, therefore this hunk is moved into
a separate function which is called by virSecurityManagerCheckAllLabel that
checks both the domain's security model and devices' security model.
https://bugzilla.redhat.com/show_bug.cgi?id=1165485
Signed-off-by: Ján Tomko <jtomko@redhat.com>
We do have a check for valid per-domain security model, however we still
do permit an invalid security model for a domain's device (those which
are specified with <source> element).
This patch introduces a new function virSecurityManagerCheckAllLabel
which compares user specified security model against currently
registered security drivers. That being said, it also permits 'none'
being specified as a device security model.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1165485
Signed-off-by: Ján Tomko <jtomko@redhat.com>
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.
When using qemuProcessAttach to attach a qemu process,
the DAC label is not filled correctly.
Introduce a new function to get the uid:gid from the system
and fill the label.
This fixes the daemon crash when 'virsh screenshot' is called:
https://bugzilla.redhat.com/show_bug.cgi?id=1161831
It also fixes qemu-attach after the prerequisite of this patch
(commit f8c1fb3) was pushed out of order.
Signed-off-by: Luyao Huang <lhuang@redhat.com>
Signed-off-by: Ján Tomko <jtomko@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1082521
Support for shared hostdev's was added in a number of commits, initially
starting with 'f2c1d9a80' and most recently commit id 'fd243fc4' to fix
issues with the initial implementation. Missed in all those changes was
the need to mimic the virSELinux{Set|Restore}SecurityDiskLabel code to
handle the "shared" (or shareable) and readonly options when Setting
or Restoring the SELinux labels.
This patch will adjust the virSecuritySELinuxSetSecuritySCSILabel to not
use the virSecuritySELinuxSetSecurityHostdevLabelHelper in order to set
the label. Rather follow what the Disk code does by setting the label
differently based on whether shareable/readonly is set. This patch will
also modify the virSecuritySELinuxRestoreSecuritySCSILabel to follow
the same logic as virSecuritySELinuxRestoreSecurityImageLabelInt and not
restore the label if shared/readonly
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>
https://bugzilla.redhat.com/show_bug.cgi?id=1147057
The code for relabelling the TAP FD is there due to a race. When
libvirt creates a /dev/tapN device it's labeled as
'system_u:object_r:device_t:s0' by default. Later, when
udev/systemd reacts to this device, it's relabelled to the
expected label 'system_u:object_r:tun_tap_device_t:s0'. Hence, we
have a code that relabels the device, to cut the race down. For
more info see ae368ebfcc.
But the problem is, the relabel function is called on all TUN/TAP
devices. Yes, on /dev/net/tun too. This is however a special kind
of device - other processes uses it too. We shouldn't touch it's
label then.
Ideally, there would an API in SELinux that would label just the
passed FD and not the underlying path. That way, we wouldn't need
to care as we would be not labeling /dev/net/tun but the FD
passed to the domain. Unfortunately, there's no such API so we
have to workaround until then.
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The check for ISCSI devices was missing a check of subsys type, which
meant we could skip labelling of other host devices as well. This fixes
USB hotplug on F21
https://bugzilla.redhat.com/show_bug.cgi?id=1145968
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.
https://bugzilla.redhat.com/show_bug.cgi?id=1141879
A long time ago I've implemented support for so called multiqueue
net. The idea was to let guest network traffic be processed by
multiple host CPUs and thus increasing performance. However, this
behavior is enabled by QEMU via special ioctl() iterated over the
all tap FDs passed in by libvirt. Unfortunately, SELinux comes in
and disallows the ioctl() call because the /dev/net/tun has label
system_u:object_r:tun_tap_device_t:s0 and 'attach_queue' ioctl()
is not allowed on tun_tap_device_t type. So after discussion with
a SELinux developer we've decided that the FDs passed to the QEMU
should be labelled with svirt_t type and SELinux policy will
allow the ioctl(). Therefore I've made a patch
(cf976d9dcf) that does exactly this. The patch
was fixed then by a443193139 and
b635b7a1af. However, things are not
that easy - even though the API to label FD is called
(fsetfilecon_raw) the underlying file is labelled too! So
effectively we are mangling /dev/net/tun label. Yes, that broke
dozen of other application from openvpn, or boxes, to qemu
running other domains.
The best solution would be if SELinux provides a way to label an
FD only, which could be then labeled when passed to the qemu.
However that's a long path to go and we should fix this
regression AQAP. So I went to talk to the SELinux developer again
and we agreed on temporary solution that:
1) All the three patches are reverted
2) SELinux temporarily allows 'attach_queue' on the
tun_tap_device_t
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
I've noticed two problem with the automatically created NVRAM varstore
file. The first, even though I run qemu as root:root for some reason I
get Permission denied when trying to open the _VARS.fd file. The
problem is, the upper directory misses execute permissions, which in
combination with us dropping some capabilities result in EPERM.
The next thing is, that if I switch SELinux to enforcing mode, I get
another EPERM because the vars file is not labeled correctly. It is
passed to qemu as disk and hence should be labelled as disk. QEMU may
write to it eventually, so this is different to kernel or initrd.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
After a4431931 the TAP FDs ale labeled with image label instead
of the process label. On the other hand, the commit was
incomplete as a few lines above, there's still old check for the
process label presence while it should be check for the image
label instead.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
QEMU now supports UEFI with the following command line:
-drive file=/usr/share/OVMF/OVMF_CODE.fd,if=pflash,format=raw,unit=0,readonly=on \
-drive file=/usr/share/OVMF/OVMF_VARS.fd,if=pflash,format=raw,unit=1 \
where the first line reflects <loader> and the second one <nvram>.
Moreover, these two lines obsolete the -bios argument.
Note that UEFI is unusable without ACPI. This is handled properly now.
Among with this extension, the variable file is expected to be
writable and hence we need security drivers to label it.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Acked-by: Laszlo Ersek <lersek@redhat.com>
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>
For security type='none' libvirt according to the docs should not
generate seclabel be it for selinux or any model. So, skip the
reservation of labels when type is none.
Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
The cleanup in commit cf976d9d used secdef->label to label the tap
FDs, but that is not possible since it's process-only label (svirt_t)
and not a object label (e.g. svirt_image_t). Starting a domain failed
with EPERM, but simply using secdef->imagelabel instead of
secdef->label fixes it.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=1095636
When starting up the domain the domain's NICs are allocated. As of
1f24f682 (v1.0.6) we are able to use multiqueue feature on virtio
NICs. It breaks network processing into multiple queues which can be
processed in parallel by different host CPUs. The queues are, however,
created by opening /dev/net/tun several times. Unfortunately, only the
first FD in the row is labelled so when turning the multiqueue feature
on in the guest, qemu will get AVC denial. Make sure we label all the
FDs needed.
Moreover, the default label of /dev/net/tun doesn't allow
attaching a queue:
type=AVC msg=audit(1399622478.790:893): avc: denied { attach_queue }
for pid=7585 comm="qemu-kvm"
scontext=system_u:system_r:svirt_t:s0:c638,c877
tcontext=system_u:system_r:virtd_t:s0-s0:c0.c1023
tclass=tun_socket
And as suggested by SELinux maintainers, the tun FD should be labeled
as svirt_t. Therefore, we don't need to adjust any range (as done
previously by Guannan in ae368ebf) rather set the seclabel of the
domain directly.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Create the structures and API's to hold and manage the iSCSI host device.
This extends the 'scsi_host' definitions added in commit id '5c811dce'.
A future patch will add the XML parsing, but that code requires some
infrastructure to be in place first in order to handle the differences
between a 'scsi_host' and an 'iSCSI host' device.
Split virDomainHostdevSubsysSCSI further. In preparation for having
either SCSI or iSCSI data, create a union in virDomainHostdevSubsysSCSI
to contain just a virDomainHostdevSubsysSCSIHost to describe the
'scsi_host' host device
To integrate the security driver with the storage driver we need to
pass a callback for a function that will chown storage volumes.
Introduce and document the callback prototype.
When restoring security labels in the dac driver the code would resolve
the file path and use the resolved one to be chown-ed. The setting code
doesn't do that. Remove the unnecessary code.
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>
This negation in names of boolean variables is driving me insane. The
code is much more readable if we drop the 'no-' prefix. Well, at least
for me.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Add security driver functions to label separate storage images using the
virStorageSource definition. This will help to avoid the need to do ugly
changes to the disk struct and use the source directly.
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.
The function headers contain type on the same line as the name. When
combined with usage of ATTRIBUTE_UNUSED, the function headers were very
long. Shorten them by breaking the line after the type.
virSecurityManagerSetDiskLabel and virSecurityManagerRestoreDiskLabel
don't have complementary semantics. Document the semantics to avoid
possible problems.
I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.
I'm going to add functions that will deal with individual image files
rather than whole disks. Rename the security function to make room for
the new one.
