c4f3c955d5
Commit 6bcf25017bc6 ("virDomainMemoryPeek API") introduced memory peek
and commit 9936aecfd1b4 ("qemu: Implement the driver methods")
introduced screenshot. Both of them will put temporary files in
/var/cache/libvirt/qemu, and the temporary files are created by QEMU.
Therefore, the ownership of /var/cache/libvirt/qemu should be changed to
user and group configured in qemu.conf to make sure that QEMU process
can create and write files in the cache directory.
Libvirt will only put the temporary files in /var/cache/libvirt/qemu
until commit cbde35899b90 ("Cache result of QEMU capabilities
extraction"), which will put the cache of QEMU capabilities in
'capabilities' subdir of the cache directory. Because the capabilities
is used by libvirt, the ownership of both 'capabilities' subdir and
capabilities files are root. However, when QEMU process runs as a
regular user (e.g. qemu user), the ownership of /var/cache/libvirt/qemu
will be changed to qemu:qemu while that of
/var/cache/libvirt/qemu/capabilities will be still root:root. Then the
regular user could spoof different capabilities, which maybe lead to
denial of service.
Since the previous patch has move the temp files of screenshot and
memory peek to per-domain directory, no one except domain capabilities
uses cacheDir currently. And since domain capabilities are used by
libvirtd instead of QEMU, no need to change the ownership of cacheDir to
qemu:qemu explicitly.
Signed-off-by: Peng Liang <liangpeng10@huawei.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser
General Public License, version 2.1 (or later). Some parts of the code
that are not part of the C library may have the more restrictive GNU
General Public License, version 2.0 (or later). See the files
COPYING.LESSER and COPYING for full license
terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: