This patch series implements the AppArmor security driver for sVirt. This implementation was developed for the Ubuntu AppArmorLibvirtProfile specification[1], but is general enough for any AppArmor deployment (such as Ubuntu, *SUSE and Mandriva). This patch has seen quite a bit of real world testing in Ubuntu 9.10 (our development release) in our 0.7.0-1ubuntu3 package. I did make a few small changes after going through HACKING, but mostly I got the tests going and added documentation. DESIGN ------ When a virtual machine is started, determine if a profile is currently defined for the machine, and use it if available. If not, generate a new profile for the machine based on a template, which is by default a very restrictive profile allowing access to disk files, and anything else needed to run, such as the pid, monitor and log files. Virtual machines should have a unique profile specific to that machine. To ensure uniqueness, the profile name will be derived from the UUID of the virtual machine. These profiles should be configurable, either by adjusting the profile template for new machines, creating/modifying the VM profile directly or through the use of AppArmor abstractions. This will allow for administrators to fine-tune confinement for individual machines if desired. If enabled at compile time, the sVirt security model will be activated if AppArmor is available on the host OS and a profile for the libvirtd daemon is loaded when libvirtd is started. libvirtd should not be allowed to create arbitrary profiles or modify profiles directly, so as to not allow libvirtd to potentially (ie via a security bug in libvirtd itself) bootstrap out of AppArmor confinement. Because root privileges are needed to manipulate AppArmor profiles, qemu:///session will not be supported at this time, but the implementation must allow for a confined libvirtd with qemu:///session guests running unconfined. This can be revisited when AppArmor supports per-user profiles. Please see the specification[1] for more details. PATCHES ------- The patches are all against trunk as of yesterday. Testing was done on trunk and there seem to be no regressions over the the 0.7.0-1ubuntu3 package in Ubuntu. [PATCH 1*] patch_1a_reenable-nonfile-labels.patch: When James Morris originally submitted his sVirt patches (as seen in libvirt 0.6.1), he did not require on disk labelling for virSecurityDomainRestoreImageLabel. A later commit[2] changed this behavior to assume on disk labelling, which halts implementations for path-based MAC systems such as AppArmor and TOMOYO where vm->def->seclabel is required to obtain the label. This patch simply adds the 'virDomainObjPtr vm' argument back to *RestoreImageLabel. patch_1b_optional.patch: Due to the above change, 'make syntax-check' fails because SELinuxRestoreSecurityImageLabel() does not use the 'virDomainObjPtr vm'. patch_1b_optional.patch is a simple patch to fix this by checking if vm->def->seclabel == NULL and returns with error if it does. I realize this may not be desired in the long term, but it should be harmless enough to include. [PATCH 2] patch_2_security_c.patch: Updates src/security.c for AppArmor [PATCH 3] patch_3_security_apparmor.patch: Adds security_apparmor.c, security_apparmor.h, virt-aa-helper.c and updates po/POTFILES.in. virt-aa-helper.c is a new binary which is used exclusively by the AppArmor security driver to manipulate AppArmor. These files compile without warning and pass syntax-check. [PATCH 4] patch_4_tests.patch: Adds tests for virt-aa-helper and the security driver. secaatest.c is identical to seclabeltest.c except it initializes the 'apparmor' driver instead of 'selinux'. These tests are integrated into 'make check' and pass. [PATCH 5] patch_5_docs.patch: Updates docs/drvqemu.html.in for AppArmor and adds profile examples to examples/apparmor. [PATCH 6] patch_6_autoconf.patch: Updates Makefile.am and configure.in for AppArmor. It is based on and should operate the same as the SELinux configuration. Caveats and known issues: 1. it does not take advantage of the recent host device labelling functionality yet 2. it does not properly handle hot-plugging of devices yet 3. qemu:///session runs unconfined (see above) Thanks! Jamie (jdstrand on Freenode and OFTC) [1] https://wiki.ubuntu.com/SecurityTeam/Specifications/AppArmorLibvirtProfile [2] http://libvirt.org/git/?p=libvirt.git;a=commit;h=c86afc85ee0d1ec6d76c2d25... -- Jamie Strandboge | http://www.canonical.com