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Eric Blake
eb7ec2312b
event: filter global events by domain:getattr ACL [CVE-2014-0028]
Ever since ACL filtering was added in commit 7639736 (v1.1.1), a user could still use event registration to obtain access to a domain that they could not normally access via virDomainLookup* or virConnectListAllDomains and friends. We already have the framework in the RPC generator for creating the filter, and previous cleanup patches got us to the point that we can now wire the filter through the entire object event stack. Furthermore, whether or not domain:getattr is honored, use of global events is a form of obtaining a list of networks, which is covered by connect:search_domains added in a93cd08 (v1.1.0). Ideally, we'd have a way to enforce connect:search_domains when doing global registrations while omitting that check on a per-domain registration. But this patch just unconditionally requires connect:search_domains, even when no list could be obtained, based on the following observations: 1. Administrators are unlikely to grant domain:getattr for one or all domains while still denying connect:search_domains - a user that is able to manage domains will want to be able to manage them efficiently, but efficient management includes being able to list the domains they can access. The idea of denying connect:search_domains while still granting access to individual domains is therefore not adding any real security, but just serves as a layer of obscurity to annoy the end user. 2. In the current implementation, domain events are filtered on the client; the server has no idea if a domain filter was requested, and must therefore assume that all domain event requests are global. Even if we fix the RPC protocol to allow for server-side filtering for newer client/server combos, making the connect:serach_domains ACL check conditional on whether the domain argument was NULL won't benefit older clients. Therefore, we choose to document that connect:search_domains is a pre-requisite to any domain event management. Network events need the same treatment, with the obvious change of using connect:search_networks and network:getattr. * src/access/viraccessperm.h (VIR_ACCESS_PERM_CONNECT_SEARCH_DOMAINS) (VIR_ACCESS_PERM_CONNECT_SEARCH_NETWORKS): Document additional effect of the permission. * src/conf/domain_event.h (virDomainEventStateRegister) (virDomainEventStateRegisterID): Add new parameter. * src/conf/network_event.h (virNetworkEventStateRegisterID): Likewise. * src/conf/object_event_private.h (virObjectEventStateRegisterID): Likewise. * src/conf/object_event.c (_virObjectEventCallback): Track a filter. (virObjectEventDispatchMatchCallback): Use filter. (virObjectEventCallbackListAddID): Register filter. * src/conf/domain_event.c (virDomainEventFilter): New function. (virDomainEventStateRegister, virDomainEventStateRegisterID): Adjust callers. * src/conf/network_event.c (virNetworkEventFilter): New function. (virNetworkEventStateRegisterID): Adjust caller. * src/remote/remote_protocol.x (REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER) (REMOTE_PROC_CONNECT_DOMAIN_EVENT_REGISTER_ANY) (REMOTE_PROC_CONNECT_NETWORK_EVENT_REGISTER_ANY): Generate a filter, and require connect:search_domains instead of weaker connect:read. * src/test/test_driver.c (testConnectDomainEventRegister) (testConnectDomainEventRegisterAny) (testConnectNetworkEventRegisterAny): Update callers. * src/remote/remote_driver.c (remoteConnectDomainEventRegister) (remoteConnectDomainEventRegisterAny): Likewise. * src/xen/xen_driver.c (xenUnifiedConnectDomainEventRegister) (xenUnifiedConnectDomainEventRegisterAny): Likewise. * src/vbox/vbox_tmpl.c (vboxDomainGetXMLDesc): Likewise. * src/libxl/libxl_driver.c (libxlConnectDomainEventRegister) (libxlConnectDomainEventRegisterAny): Likewise. * src/qemu/qemu_driver.c (qemuConnectDomainEventRegister) (qemuConnectDomainEventRegisterAny): Likewise. * src/uml/uml_driver.c (umlConnectDomainEventRegister) (umlConnectDomainEventRegisterAny): Likewise. * src/network/bridge_driver.c (networkConnectNetworkEventRegisterAny): Likewise. * src/lxc/lxc_driver.c (lxcConnectDomainEventRegister) (lxcConnectDomainEventRegisterAny): Likewise. Signed-off-by: Eric Blake <eblake@redhat.com> (cherry picked from commit f9f56340539d609cdc2e9d4ab812b9f146c3f100) Conflicts: src/conf/object_event.c - not backporting event refactoring src/conf/object_event_private.h - likewise src/conf/network_event.c - not backporting network events src/conf/network_event.h - likewise src/network/bridge_driver.c - likewise src/access/viraccessperm.h - likewise src/remote/remote_protocol.x - likewise src/conf/domain_event.c - includes code that upstream has in object_event src/conf/domain_event.h - context src/libxl/libxl_driver.c - context src/lxc/lxc_driver.c - context src/remote/remote_driver.c - context, not backporting network events src/test/test_driver.c - context, not backporting network events src/uml/uml_driver.c - context src/xen/xen_driver.c - context
LibVirt : simple API for virtualization Libvirt is a C toolkit to interact with the virtualization capabilities of recent versions of Linux (and other OSes). It is free software available under the GNU Lesser General Public License. Virtualization of the Linux Operating System means the ability to run multiple instances of Operating Systems concurrently on a single hardware system where the basic resources are driven by a Linux instance. The library aim at providing long term stable C API initially for the Xen paravirtualization but should be able to integrate other virtualization mechanisms if needed. Daniel Veillard <veillard@redhat.com>
Description
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.
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