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>
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.
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.
The image labels are stored in the virStorageSource struct. Convert the
virDomainDiskDefGetSecurityLabelDef helper not to use the full disk def
and move it appropriately.
A network disk might actually be backed by local storage. Also the path
iterator actually handles networked disks well now so remove the code
that skips the labelling in dac and selinux security driver.
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>
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.
The code in virstoragefile.c is getting more complex as I
consolidate backing chain handling code. But for the setuid
virt-login-shell, we don't need to crawl backing chains. It's
easier to audit things for setuid security if there are fewer
files involved, so this patch moves the one function that
virFileOpen() was actually relying on to also live in virfile.c.
* src/util/virstoragefile.c (virStorageFileIsSharedFS)
(virStorageFileIsSharedFSType): Move...
* src/util/virfile.c (virFileIsSharedFS, virFileIsSharedFSType):
...to here, and rename.
(virFileOpenAs): Update caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetFileconHelper)
(virSecuritySELinuxSetSecurityAllLabel)
(virSecuritySELinuxRestoreSecurityImageLabelInt): Likewise.
* src/security/security_dac.c
(virSecurityDACRestoreSecurityImageLabelInt): Likewise.
* src/qemu/qemu_driver.c (qemuOpenFileAs): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/util/virstoragefile.h: Adjust declarations.
* src/util/virfile.h: Likewise.
* src/libvirt_private.syms (virfile.h, virstoragefile.h): Move
symbols as appropriate.
Signed-off-by: Eric Blake <eblake@redhat.com>
In order to reuse the newly-created host-side disk struct in
the virstoragefile backing chain code, I first have to move
it to util/. This starts the process, by first moving the
security label structures.
* src/conf/domain_conf.h (virDomainDefGenSecurityLabelDef)
(virDomainDiskDefGenSecurityLabelDef, virSecurityLabelDefFree)
(virSecurityDeviceLabelDefFree, virSecurityLabelDef)
(virSecurityDeviceLabelDef): Move...
* src/util/virseclabel.h: ...to new file.
(virSecurityLabelDefNew, virSecurityDeviceLabelDefNew): Rename the
GenSecurity functions.
* src/qemu/qemu_process.c (qemuProcessAttach): Adjust callers.
* src/security/security_manager.c (virSecurityManagerGenLabel):
Likewise.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityFileLabel): Likewise.
* src/util/virseclabel.c: New file.
* src/conf/domain_conf.c: Move security code, and fix fallout.
* src/Makefile.am (UTIL_SOURCES): Build new file.
* src/libvirt_private.syms (domain_conf.h): Move symbols...
(virseclabel.h): ...to new section.
Signed-off-by: Eric Blake <eblake@redhat.com>
It's finally time to start tracking disk backing chains in
<domain> XML. The first step is to start refactoring code
so that we have an object more convenient for representing
each host source resource in the context of a single guest
<disk>. Ultimately, I plan to move the new type into src/util
where it can be reused by virStorageFile, but to make the
transition easier to review, this patch just creates the
new type then fixes everything until it compiles again.
* src/conf/domain_conf.h (_virDomainDiskDef): Split...
(_virDomainDiskSourceDef): ...to new struct.
(virDomainDiskAuthClear): Use new type.
* src/conf/domain_conf.c (virDomainDiskDefFree): Split...
(virDomainDiskSourceDefClear): ...to new function.
(virDomainDiskGetType, virDomainDiskSetType)
(virDomainDiskGetSource, virDomainDiskSetSource)
(virDomainDiskGetDriver, virDomainDiskSetDriver)
(virDomainDiskGetFormat, virDomainDiskSetFormat)
(virDomainDiskAuthClear, virDomainDiskGetActualType)
(virDomainDiskDefParseXML, virDomainDiskSourceDefFormat)
(virDomainDiskDefFormat, virDomainDiskDefForeachPath)
(virDomainDiskDefGetSecurityLabelDef)
(virDomainDiskSourceIsBlockType): Adjust all users.
* src/lxc/lxc_controller.c (virLXCControllerSetupDisk):
Likewise.
* src/lxc/lxc_driver.c (lxcDomainAttachDeviceMknodHelper):
Likewise.
* src/qemu/qemu_command.c (qemuAddRBDHost, qemuParseRBDString)
(qemuParseDriveURIString, qemuParseGlusterString)
(qemuParseISCSIString, qemuParseNBDString)
(qemuDomainDiskGetSourceString, qemuBuildDriveStr)
(qemuBuildCommandLine, qemuParseCommandLineDisk)
(qemuParseCommandLine): Likewise.
* src/qemu/qemu_conf.c (qemuCheckSharedDevice)
(qemuAddISCSIPoolSourceHost, qemuTranslateDiskSourcePool):
Likewise.
* src/qemu/qemu_driver.c (qemuDomainUpdateDeviceConfig)
(qemuDomainPrepareDiskChainElement)
(qemuDomainSnapshotCreateInactiveExternal)
(qemuDomainSnapshotPrepareDiskExternalBackingInactive)
(qemuDomainSnapshotPrepareDiskInternal)
(qemuDomainSnapshotPrepare)
(qemuDomainSnapshotCreateSingleDiskActive)
(qemuDomainSnapshotUndoSingleDiskActive)
(qemuDomainBlockPivot, qemuDomainBlockJobImpl)
(qemuDomainBlockCopy, qemuDomainBlockCommit): Likewise.
* src/qemu/qemu_migration.c (qemuMigrationIsSafe): Likewise.
* src/qemu/qemu_process.c (qemuProcessGetVolumeQcowPassphrase)
(qemuProcessInitPasswords): Likewise.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityFileLabel): Likewise.
* src/storage/storage_driver.c (virStorageFileInitFromDiskDef):
Likewise.
* tests/securityselinuxlabeltest.c (testSELinuxLoadDef):
Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Part of a series of cleanups to use new accessor methods.
* src/security/security_dac.c (virSecurityDACSetSecurityImageLabel)
(virSecurityDACRestoreSecurityImageLabelInt)
(virSecurityDACSetSecurityAllLabel): Use accessors.
* src/security/security_selinux.c
(virSecuritySELinuxRestoreSecurityImageLabelInt)
(virSecuritySELinuxSetSecurityImageLabel)
(virSecuritySELinuxSetSecurityAllLabel): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Per the documentation, is_selinux_enabled() returns -1 on error.
Account for this. Previously when -1 was being returned the condition
would still be true. I was noticing this because on my system that has
selinux disabled I was getting this in the libvirt.log every 5
seconds:
error : virIdentityGetSystem:173 : Unable to lookup SELinux process context: Invalid argument
With this patch applied, I no longer get these messages every 5
seconds. I am submitting this in case its deemed useful for inclusion.
Anyone have any comments on this change? This is a patch off current
master.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit 2ce63c1 added imagelabel generation when relabeling is turned
off. But we weren't filling out the sensitivity for type 'none' labels,
resulting in an invalid label:
$ virsh managedsave domain
error: unable to set security context 'system_u:object_r:svirt_image_t'
on fd 28: Invalid argument
To support passing the path of the test data to the utils, one
more argument is added to virSCSIDeviceGetSgName,
virSCSIDeviceGetDevName, and virSCSIDeviceNew, and the related
code is changed accordingly.
Later tests for the scsi utils will be based on this patch.
Signed-off-by: Osier Yang <jyang@redhat.com>
Unlike the host devices of other types, SCSI host device XML supports
"shareable" tag. This patch introduces it for the virSCSIDevice struct
for a later patch use (to detect if the SCSI device is shareable when
preparing the SCSI host device in QEMU driver).
https://bugzilla.redhat.com/show_bug.cgi?id=996543
When starting up a domain, the SELinux labeling is done depending on
current configuration. If the labeling fails we check for possible
causes, as not all labeling failures are fatal. For example, if the
labeled file is on NFS which lacks SELinux support, the file can still
be readable to qemu process. These cases are distinguished by the errno
code: NFS without SELinux support returns EOPNOTSUPP. However, we were
missing one scenario. In case there's a read-only disk on a read-only
NFS (and possibly any FS) and the labeling is just optional (not
explicitly requested in the XML) there's no need to make the labeling
error fatal. In other words, read-only file on read-only NFS can fail to
be labeled, but be readable at the same time.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
For a while we're have random failures of 'securityselinuxtest'
which were not at all reproducible. Fortunately we finally
caught a failure with VIR_TEST_DEBUG=1 enabled. This revealed
TEST: securityselinuxtest
1) GenLabel "dynamic unconfined, s0, c0.c1023" ... OK
2) GenLabel "dynamic unconfined, s0, c0.c1023" ... OK
3) GenLabel "dynamic unconfined, s0, c0.c1023" ... OK
4) GenLabel "dynamic virtd, s0, c0.c1023" ... OK
5) GenLabel "dynamic virtd, s0, c0.c10" ... OK
6) GenLabel "dynamic virtd, s2-s3, c0.c1023" ... OK
7) GenLabel "dynamic virtd, missing range" ... Category two 1024 is out of range 0-1023
FAILED
FAIL: securityselinuxtest
And sure enough we had an off-by-1 in the MCS range code when
the current process has no range set. The test suite randomly
allocates 2 categories from 0->1024 so the chances of hitting
this in the test suite were slim indeed :-)
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can). But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).
Fix up offenders in src/security.
* src/security/security_apparmor.c (reload_profile)
(AppArmorSetSecurityHostdevLabelHelper)
(AppArmorReleaseSecurityLabel, AppArmorRestoreSecurityAllLabel)
(AppArmorSetSecurityProcessLabel)
(AppArmorSetSecurityChildProcessLabel)
(AppArmorSetSecurityImageLabel, AppArmorSecurityVerify)
(AppArmorSetSecurityHostdevLabel)
(AppArmorRestoreSecurityHostdevLabel, AppArmorSetFDLabel): Drop
needless const.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityFileLabel): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=924153
Commit 904e05a2 (v0.9.9) added a per-<disk> seclabel element with
an attribute relabel='no' in order to try and minimize the
impact of shutdown delays when an NFS server disappears. The idea
was that if a disk is on NFS and can't be labeled in the first
place, there is no need to attempt the (no-op) relabel on domain
shutdown. Unfortunately, the way this was implemented was by
modifying the domain XML so that the optimization would survive
libvirtd restart, but in a way that is indistinguishable from an
explicit user setting. Furthermore, once the setting is turned
on, libvirt avoids attempts at labeling, even for operations like
snapshot or blockcopy where the chain is being extended or pivoted
onto non-NFS, where SELinux labeling is once again possible. As
a result, it was impossible to do a blockcopy to pivot from an
NFS image file onto a local file.
The solution is to separate the semantics of a chain that must
not be labeled (which the user can set even on persistent domains)
vs. the optimization of not attempting a relabel on cleanup (a
live-only annotation), and using only the user's explicit notation
rather than the optimization as the decision on whether to skip
a label attempt in the first place. When upgrading an older
libvirtd to a newer, an NFS volume will still attempt the relabel;
but as the avoidance of a relabel was only an optimization, this
shouldn't cause any problems.
In the ideal future, libvirt will eventually have XML describing
EVERY file in the backing chain, with each file having a separate
<seclabel> element. At that point, libvirt will be able to track
more closely which files need a relabel attempt at shutdown. But
until we reach that point, the single <seclabel> for the entire
<disk> chain is treated as a hint - when a chain has only one
file, then we know it is accurate; but if the chain has more than
one file, we have to attempt relabel in spite of the attribute,
in case part of the chain is local and SELinux mattered for that
portion of the chain.
* src/conf/domain_conf.h (_virSecurityDeviceLabelDef): Add new
member.
* src/conf/domain_conf.c (virSecurityDeviceLabelDefParseXML):
Parse it, for live images only.
(virSecurityDeviceLabelDefFormat): Output it.
(virDomainDiskDefParseXML, virDomainChrSourceDefParseXML)
(virDomainDiskSourceDefFormat, virDomainChrDefFormat)
(virDomainDiskDefFormat): Pass flags on through.
* src/security/security_selinux.c
(virSecuritySELinuxRestoreSecurityImageLabelInt): Honor labelskip
when possible.
(virSecuritySELinuxSetSecurityFileLabel): Set labelskip, not
norelabel, if labeling fails.
(virSecuritySELinuxSetFileconHelper): Fix indentation.
* docs/formatdomain.html.in (seclabel): Document new xml.
* docs/schemas/domaincommon.rng (devSeclabel): Allow it in RNG.
* tests/qemuxml2argvdata/qemuxml2argv-seclabel-*-labelskip.xml:
* tests/qemuxml2argvdata/qemuxml2argv-seclabel-*-labelskip.args:
* tests/qemuxml2xmloutdata/qemuxml2xmlout-seclabel-*-labelskip.xml:
New test files.
* tests/qemuxml2argvtest.c (mymain): Run the new tests.
* tests/qemuxml2xmltest.c (mymain): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The imagelabel SELinux label was only generated when relabeling was
enabled. This prohibited labeling of files created by libvirt that need
to be labeled even if relabeling is turned off.
The only codepath this change has direct impact on is labeling of FDs
passed to qemu which is always safe in current state.
I realized after the fact that it's probably better in the long run to
give this function a name that matches the name of the link used in
sysfs to hold the group (iommu_group).
I'm changing it now because I'm about to add several more functions
that deal with iommu groups.
To not introduce more redundant code, helpers are added for
both "selinux", "dac", and "apparmor" backends.
Signed-off-by: Han Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: Osier Yang <jyang@redhat>
v2.5 - v3:
* Splitted from 8/10 of v2.5
* Don't forget the other backends (DAC, and apparmor)
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
If virPCIDeviceGetVFIOGroupDev() failed,
virSecurity*(Set|Restore)HostdevLabel() would fail to free a
virPCIDevice that had been allocated.
These leaks were all introduced (by me) very recently, in commit
f0bd70a.
This isn't strictly speaking a bugfix, but I realized I'd gotten a bit
too verbose when I chose the names for
VIR_DOMAIN_HOSTDEV_PCI_BACKEND_TYPE_*. This shortens them all a bit.
Legacy kvm style pci device assignment requires changes to the
labelling of several sysfs files for each device, but for vfio device
assignment, the only thing that needs to be relabelled/chowned is the
"group" device for the group that contains the device to be assigned.
There will soon be other items related to pci hostdevs that need to be
in the same part of the hostdevsubsys union as the pci address (which
is currently a single member called "pci". This patch replaces the
single member named pci with a struct named pci that contains a single
member named "addr".
Detected by a simple Shell script:
for i in $(git ls-files -- '*.[ch]'); do
awk 'BEGIN {
fail=0
}
/# *include.*\.h/{
match($0, /["<][^">]*[">]/)
arr[substr($0, RSTART+1, RLENGTH-2)]++
}
END {
for (key in arr) {
if (arr[key] > 1) {
fail=1
printf("%d %s\n", arr[key], key)
}
}
if (fail == 1)
exit 1
}' $i
if test $? != 0; then
echo "Duplicate header(s) in $i"
fi
done;
A later patch will add the syntax-check to avoid duplicate
headers.
The virDomainDefGetSecurityLabelDef was modifying the domain XML.
It tried to find a seclabel corresponding to given sec driver. If the
label wasn't found, the function created one which is wrong. In fact
it's security manager which should modify this part of domain XML.
Normally libvirtd should run with a SELinux label
system_u:system_r:virtd_t:s0-s0:c0.c1023
If a user manually runs libvirtd though, it is sometimes
possible to get into a situation where it is running
system_u:system_r:init_t:s0
The SELinux security driver isn't expecting this and can't
parse the security label since it lacks the ':c0.c1023' part
causing it to complain
internal error Cannot parse sensitivity level in s0
This updates the parser to cope with this, so if no category
is present, libvirtd will hardcode the equivalent of c0.c1023.
Now this won't work if SELinux is in Enforcing mode, but that's
not an issue, because the user can only get into this problem
if in Permissive mode. This means they can now start VMs in
Permissive mode without hitting that parsing error
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Pull the code which parses the current process MCS range
out of virSecuritySELinuxMCSFind and into a new method
virSecuritySELinuxMCSGetProcessRange.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The body of the loop in virSecuritySELinuxMCSFind would
directly 'return NULL' on OOM, instead of jumping to the
cleanup label. This caused a leak of several local vars.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Coverity found the DACGenLabel was checking for mgr == NULL after a
possible dereference; however, in order to get into the function the
virSecurityManagerGenLabel would have already dereferenced sec_managers[i]
so the check was unnecessary. Same check is made in SELinuxGenSecurityLabel.
The existing virSecurityManagerSetProcessLabel() API is designed so
that it must be called after forking the child process, but before
exec'ing the child. Due to the way the virCommand API works, that
means it needs to be put in a "hook" function that virCommand is told
to call out to at that time.
Setting the child process label is a basic enough need when executing
any process that virCommand should have a method of doing that. But
virCommand must be told what label to set, and only the security
driver knows the answer to that question.
The new virSecurityManagerSet*Child*ProcessLabel() API is the way to
transfer the knowledge about what label to set from the security
driver to the virCommand object. It is given a virCommandPtr, and each
security driver calls the appropriate virCommand* API to tell
virCommand what to do between fork and exec.
1) in the case of the DAC security driver, it calls
virCommandSetUID/GID() to set a uid and gid that must be set for the
child process.
2) for the SELinux security driver, it calls
virCommandSetSELinuxLabel() to save a copy of the char* that will be
sent to setexeccon_raw() *after forking the child process*.
3) for the AppArmor security drivers, it calls
virCommandSetAppArmorProfile() to save a copy of the char* that will
be sent to aa_change_profile() *after forking the child process*.
With this new API in place, we will be able to remove
virSecurityManagerSetProcessLabel() from any virCommand pre-exec
hooks.
(Unfortunately, the LXC driver uses clone() rather than virCommand, so
it can't take advantage of this new security driver API, meaning that
we need to keep around the older virSecurityManagerSetProcessLabel(),
at least for now.)
On RHEL 5, I got:
security/security_selinux.c: In function 'getContext':
security/security_selinux.c:971: warning: unused parameter 'mgr' [-Wunused-parameter]
* src/security/security_selinux.c (getContext): Mark potentially
unused parameter.
The security manager drivers are not allowed to call back
out to top level security manager APIs, since that results
in recursive mutex acquisition and thus deadlock. Remove
calls to virSecurityManagerGetModel from SELinux / AppArmor
drivers
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit id a994ef2d1 changed the mechanism to store/update the default
security label from using disk->seclabels[0] to allocating one on the
fly. That change allocated the label, but never saved it. This patch
will save the label. The new virDomainDiskDefAddSecurityLabelDef() is
a copy of the virDomainDefAddSecurityLabelDef().
Prepare to support different types of hostdevs by refactoring
the current SELinux security driver code
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When LXC labels USB devices during hotplug, it is running in
host context, so it needs to pass in a vroot path to the
container root.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virSecurityManager{Set,Restore}AllLabel methods are invoked
at domain startup/shutdown to relabel resources associated with
a domain. This works fine with QEMU, but with LXC they are in
fact both currently no-ops since LXC does not support disks,
hostdevs, or kernel/initrd files. Worse, when LXC gains support
for disks/hostdevs, they will do the wrong thing, since they
run in host context, not container context. Thus this patch
turns then into a formal no-op when used with LXC. The LXC
controller will call out to specific security manager labelling
APIs as required during startup.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The current SELinux policy only works for KVM guests, since
TCG requires the 'execmem' privilege. There is a 'virt_use_execmem'
boolean to turn this on globally, but that is unpleasant for users.
This changes libvirt to automatically use a new 'svirt_tcg_t'
context for TCG based guests. This obsoletes the previous
boolean tunable and makes things 'just work(tm)'
Since we can't assume we run with new enough policy, I also
make us log a warning message (once only) if we find the policy
lacks support. In this case we fallback to the normal label and
expect users to set the boolean tunable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The impls of virSecurityManagerGetMountOptions had no way to
return errors, since the code was treating 'NULL' as a success
value. This is somewhat pointless, since the calling code did
not want NULL in the first place and has to translate it into
the empty string "". So change the code so that the impls can
return "" directly, allowing use of NULL for error reporting
once again
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When restoring selinux labels after a VM is stopped, any non-standard
path that doesn't have a default selinux label causes the process
to stop and exit early. This isn't really an error condition IMO.
Of course the selinux API could be erroring for some other reason
but hopefully that's rare enough to not need explicit handling.
Common example here is storing disk images in a non-standard location
like under /mnt.
We used to walk the backing file chain at least twice per disk,
once to set up cgroup device whitelisting, and once to set up
security labeling. Rather than walk the chain every iteration,
which possibly includes calls to fork() in order to open root-squashed
NFS files, we can exploit the cache of the previous patch.
* src/conf/domain_conf.h (virDomainDiskDefForeachPath): Alter
signature.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Require caller
to supply backing chain via disk, if recursion is desired.
* src/security/security_dac.c
(virSecurityDACSetSecurityImageLabel): Adjust caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityImageLabel): Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup): Likewise.
(qemuSetupCgroup): Pre-populate chain.
BZ:https://bugzilla.redhat.com/show_bug.cgi?id=851981
When using macvtap, a character device gets first created by
kernel with name /dev/tapN, its selinux context is:
system_u:object_r:device_t:s0
Shortly, when udev gets notification when new file is created
in /dev, it will then jump in and relabel this file back to the
expected default context:
system_u:object_r:tun_tap_device_t:s0
There is a time gap happened.
Sometimes, it will have migration failed, AVC error message:
type=AVC msg=audit(1349858424.233:42507): avc: denied { read write } for
pid=19926 comm="qemu-kvm" path="/dev/tap33" dev=devtmpfs ino=131524
scontext=unconfined_u:system_r:svirt_t:s0:c598,c908
tcontext=system_u:object_r:device_t:s0 tclass=chr_file
This patch will label the tapfd device before qemu process starts:
system_u:object_r:tun_tap_device_t:MCS(MCS from seclabel->label)
We are currently able to work only with non-translated SELinux
contexts, but we are using functions that work with translated
contexts throughout the code. This patch swaps all SELinux context
translation relative calls with their raw sisters to avoid parsing
problems.
The problems can be experienced with mcstrans for example. The
difference is that if you have translations enabled (yum install
mcstrans; service mcstrans start), fgetfilecon_raw() will get you
something like 'system_u:object_r:virt_image_t:s0', whereas
fgetfilecon() will return 'system_u:object_r:virt_image_t:SystemLow'
that we cannot parse.
I was trying to confirm that the _raw variants were here since the dawn of
time, but the only thing I see now is that it was imported together in
the upstream repo [1] from svn, so before 2008.
Thanks Laurent Bigonville for finding this out.
[1] http://oss.tresys.com/git/selinux.git
All USB device lookup functions emit an error when they cannot find the
requested device. With this patch, their caller can choose if a missing
device is an error or normal condition.
This allows the user to control labelling of each character device
separately (the default is to inherit from the VM).
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.
* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/; If/. If/
Currently the dynamic label generation code will create labels
with a sensitivity of s0, and a category pair in the range
0-1023. This is fine when running a standard MCS policy because
libvirtd will run with a label
system_u:system_r:virtd_t:s0-s0:c0.c1023
With custom policies though, it is possible for libvirtd to have
a different sensitivity, or category range. For example
system_u:system_r:virtd_t:s2-s3:c512.c1023
In this case we must assign the VM a sensitivity matching the
current lower sensitivity value, and categories in the range
512-1023
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The code to refactor sec label handling accidentally changed the
SELinux driver to use the 'domain_context' when generating the
image label instead of the 'file_context'
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
These changes make the security drivers able to find and handle the
correct security label information when more than one label is
available. They also update the DAC driver to be used as an usual
security driver.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
This patch updates the structures that store information about each
domain and each hypervisor to support multiple security labels and
drivers. It also updates all the remaining code to use the new fields.
Signed-off-by: Marcelo Cerri <mhcerri@linux.vnet.ibm.com>
This is a fix for the object label generation. It uses a new flag for
virSecuritySELinuxGenNewContext that specifies whether the context is
for an object. If so the context role remains unchanged.
Without this fix it is not possible to start domains with image file or
block device backed storage when selinux is enabled.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
The code for picking a MCS label is about to get significantly
more complicated, so it deserves to be in a standlone method,
instead of a switch/case body.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When generating an SELinux context for a VM from the template
"system_u:system_r:svirt_t:s0", copy the role + user from the
current process instead of the template context. So if the
current process is
unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
then the VM context ends up as
unconfined_u:unconfined_r:svirt_t:s0:c386,c703
instead of
system_u:system_r:svirt_t:s0:c177,c424
Ideally the /etc/selinux/targeted/contexts/virtual_domain_context
file would have just shown the 'svirt_t' type, and not the full
context, but that can't be changed now for compatibility reasons.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virSecuritySELinuxGenNewContext method was not reporting any
errors, leaving it up to the caller to report a generic error.
In addition it could potentially trigger a strdup(NULL) in an
OOM scenario. Move all error reporting into the
virSecuritySELinuxGenNewContext method where accurate info
can be provided
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
