https://bugzilla.redhat.com/show_bug.cgi?id=1058839
Commit f9f56340 for CVE-2014-0028 almost had the right idea - we
need to check the ACL rules to filter which events to send. But
it overlooked one thing: the event dispatch queue is running in
the main loop thread, and therefore does not normally have a
current virIdentityPtr. But filter checks can be based on current
identity, so when libvirtd.conf contains access_drivers=["polkit"],
we ended up rejecting access for EVERY event due to failure to
look up the current identity, even if it should have been allowed.
Furthermore, even for events that are triggered by API calls, it
is important to remember that the point of events is that they can
be copied across multiple connections, which may have separate
identities and permissions. So even if events were dispatched
from a context where we have an identity, we must change to the
correct identity of the connection that will be receiving the
event, rather than basing a decision on the context that triggered
the event, when deciding whether to filter an event to a
particular connection.
If there were an easy way to get from virConnectPtr to the
appropriate virIdentityPtr, then object_event.c could adjust the
identity prior to checking whether to dispatch an event. But
setting up that back-reference is a bit invasive. Instead, it
is easier to delay the filtering check until lower down the
stack, at the point where we have direct access to the RPC
client object that owns an identity. As such, this patch ends
up reverting a large portion of the framework of commit f9f56340.
We also have to teach 'make check' to special-case the fact that
the event registration filtering is done at the point of dispatch,
rather than the point of registration. Note that even though we
don't actually use virConnectDomainEventRegisterCheckACL (because
the RegisterAny variant is sufficient), we still generate the
function for the purposes of documenting that the filtering
takes place.
Also note that I did not entirely delete the notion of a filter
from object_event.c; I still plan on using that for my upcoming
patch series for qemu monitor events in libvirt-qemu.so. In
other words, while this patch changes ACL filtering to live in
remote.c and therefore we have no current client of the filtering
in object_event.c, the notion of filtering in object_event.c is
still useful down the road.
* src/check-aclrules.pl: Exempt event registration from having to
pass checkACL filter down call stack.
* daemon/remote.c (remoteRelayDomainEventCheckACL)
(remoteRelayNetworkEventCheckACL): New functions.
(remoteRelay*Event*): Use new functions.
* src/conf/domain_event.h (virDomainEventStateRegister)
(virDomainEventStateRegisterID): Drop unused parameter.
* src/conf/network_event.h (virNetworkEventStateRegisterID):
Likewise.
* src/conf/domain_event.c (virDomainEventFilter): Delete unused
function.
* src/conf/network_event.c (virNetworkEventFilter): Likewise.
* src/libxl/libxl_driver.c: Adjust caller.
* src/lxc/lxc_driver.c: Likewise.
* src/network/bridge_driver.c: Likewise.
* src/qemu/qemu_driver.c: Likewise.
* src/remote/remote_driver.c: Likewise.
* src/test/test_driver.c: Likewise.
* src/uml/uml_driver.c: Likewise.
* src/vbox/vbox_tmpl.c: Likewise.
* src/xen/xen_driver.c: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
We haven't had a release with network events yet, so we are free
to fix the RPC so that it actually does what we want. Doing
client-side filtering of per-network events is inefficient if a
connection is only interested in events on a single network out
of hundreds available on the server. But to do server-side
per-network filtering, the server needs to know which network
to filter on - so we need to pass an optional network over on
registration. Furthermore, it is possible to have a client with
both a global and per-network filter; in the existing code, the
server sends only one event and the client replicates to both
callbacks. But with server-side filtering, the server will send
the event twice, so we need a way for the client to know which
callbackID is sending an event, to ensure that the client can
filter out events from a registration that does not match the
callbackID from the server. Likewise, the existing style of
deregistering by eventID alone is fine; but in the new style,
we have to remember which callbackID to delete.
This patch fixes the RPC wire definition to contain all the
needed pieces of information, and hooks into the server and
client side improvements of the previous patches, in order to
switch over to full server-side filtering of network events.
Also, since we fixed this in time, all released versions of
libvirtd that support network events also support per-network
filtering, so we can hard-code that assumption into
network_event.c.
Converting domain events to server-side filtering will require
the introduction of new RPC numbers, as well as a server
feature bit that the client can use to tell whether to use
old-style (server only supports global events) or new-style
(server supports filtered events), so that is deferred to a
later set of patches.
* src/conf/network_event.c (virNetworkEventStateRegisterClient):
Assume server-side filtering.
* src/remote/remote_protocol.x
(remote_connect_network_event_register_any_args): Add network
argument.
(remote_connect_network_event_register_any_ret): Return callbackID
instead of count.
(remote_connect_network_event_deregister_any_args): Pass
callbackID instead of eventID.
(remote_connect_network_event_deregister_any_ret): Drop unused
type.
(remote_network_event_lifecycle_msg): Add callbackID.
* daemon/remote.c
(remoteDispatchConnectNetworkEventDeregisterAny): Drop unused arg,
and deal with callbackID from client.
(remoteRelayNetworkEventLifecycle): Pass callbackID.
(remoteDispatchConnectNetworkEventRegisterAny): Likewise, and
recognize non-NULL network.
* src/remote/remote_driver.c
(remoteConnectNetworkEventRegisterAny): Pass network, and track
server side id.
(remoteConnectNetworkEventDeregisterAny): Deregister by callback id.
(remoteNetworkBuildEventLifecycle): Pass remote id to event queue.
* src/remote_protocol-structs: Regenerate.
Signed-off-by: Eric Blake <eblake@redhat.com>
Right now, the daemon side of RPC events is hard-coded to at most
one callback per eventID. But when there are hundreds of domains
or networks coupled and multiple conections, then sending every
event to every connection that wants an event, even for the
connections that only care about events for a particular object,
is inefficient. In order to track more than one callback in the
server, we need to store callbacks by more than just their
eventID. This patch rearranges the daemon side to store network
callbacks in a dynamic array, which can eventually be used for
multiple callbacks of the same eventID, although actual behavior
is unchanged without further patches to the RPC protocol. For
ease of review, domain events are saved for a later patch, as
they touch more code.
While at it, fix a bug where a malicious client could send a
negative eventID to cause network event registration to access
outside of array bounds (thankfully not a CVE, since domain
events were already doing the bounds check, and since network
events have not been released).
* daemon/libvirtd.h (daemonClientPrivate): Alter the tracking of
network events.
* daemon/remote.c (daemonClientEventCallback): New struct.
(remoteEventCallbackFree): New function.
(remoteClientInitHook, remoteRelayNetworkEventLifecycle)
(remoteClientFreeFunc)
(remoteDispatchConnectNetworkEventRegisterAny): Track network
callbacks differently.
(remoteDispatchConnectNetworkEventDeregisterAny): Enforce bounds.
Signed-off-by: Eric Blake <eblake@redhat.com>
When a client disconnects from libvirtd, all event callbacks
must be removed. This involves running the public API
virConnectDomainEventDeregisterAny
This code does not run in normal API dispatch context, so no
identity was set. The result was that the access control drivers
denied the attempt to deregister callbacks. The callbacks thus
continued to trigger after the client was free'd causing fairly
predictable use of free memory & a crash.
This can be triggered by any client with readonly access when
the ACL drivers are active.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The 'stats' variable was not initialized to NULL, so if some
early validation of the RPC call fails, it is possible to jump
to the 'cleanup' label and VIR_FREE an uninitialized pointer.
This is a security flaw, since the API can be called from a
readonly connection which can trigger the validation checks.
This was introduced in release v0.9.1 onwards by
commit 158ba8730e
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Wed Apr 13 16:21:35 2011 +0100
Merge all returns paths from dispatcher into single path
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
With the existing pkcheck (pid, start time) tuple for identifying
the process, there is a race condition, where a process can make
a libvirt RPC call and in another thread exec a setuid application,
causing it to change to effective UID 0. This in turn causes polkit
to do its permission check based on the wrong UID.
To address this, libvirt must get the UID the caller had at time
of connect() (from SO_PEERCRED) and pass a (pid, start time, uid)
triple to the pkcheck program.
This fix requires that libvirt is re-built against a version of
polkit that has the fix for its CVE-2013-4288, so that libvirt
can see 'pkg-config --variable pkcheck_supports_uid polkit-gobject-1'
Signed-off-by: Colin Walters <walters@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllSecrets call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllNWFilters call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllNodeDevices call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllInterfaces call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllNetworks call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virStoragePoolListAllVolumes call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllStoragePools call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virConnectListAllDomains call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virDomain{SnapshotListAllChildren,ListAllSnapshots}
calls were not bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The return values for the virDomainGetJobStats call were not
bounds checked. This is a robustness issue for clients if
something where to cause corruption of the RPC stream data.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The parameters for the virDomainMigrate*Params RPC calls were
not bounds checks, meaning a malicious client can cause libvirtd
to consume arbitrary memory
This issue was introduced in the 1.1.0 release of libvirt
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Since they make use of file descriptor passing, the remote protocol
methods for virDomainCreate{XML}WithFiles must be written by hand.
Signed-off-by: Daniel P. Berrange <berrange@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>
This is a recurring problem for cygwin :)
For example, see commit 23a4df88.
qemu/qemu_driver.c: In function 'qemuStateInitialize':
qemu/qemu_driver.c:691:13: error: format '%d' expects type 'int', but argument 8 has type 'uid_t' [-Wformat]
* src/qemu/qemu_driver.c (qemuStateInitialize): Add casts.
* daemon/remote.c (remoteDispatchAuthList): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
CVE-2013-1962
remoteDispatchStoragePoolListAllVolumes wasn't freeing the pool.
The pool also held a reference to the connection, preventing it from
getting freed and closing the netcf interface driver, which held two
sockets open.
Since PIDs can be reused, polkit prefers to be given
a (PID,start time) pair. If given a PID on its own,
it will attempt to lookup the start time in /proc/pid/stat,
though this is subject to races.
It is safer if the client app resolves the PID start
time itself, because as long as the app has the client
socket open, the client PID won't be reused.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Since the 'nparams' variable passed to virTypedParametersFree is
supposed to represent the size of the 'params' array, it is bad
practice to initialize it to a non-zero value, until the array
has been allocated.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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.
Ensure that the driver struct field names match the public
API names. For an API virXXXX we must have a driver struct
field xXXXX. ie strip the leading 'vir' and lowercase any
leading uppercase letters.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
A number of the remote procedure names did not match the
corresponding API names. For example, many lacked the
word 'CONNECT', others re-arranged the names. Update the
procedures so their names exactly match the API names.
Then remove the special case handling of these APIs in
the generator
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Directories python/tools/examples should include them in <> form,
though this patch allows "" form in these directories by excluding
them, a later patch will do the cleanup.
Currently the server determines whether authentication of clients
is complete, by checking whether an identity is set. This patch
removes that lame hack and replaces it with an explicit method
for changing the client auth code
* daemon/remote.c: Update for new APis
* src/libvirt_private.syms, src/rpc/virnetserverclient.c,
src/rpc/virnetserverclient.h: Remove virNetServerClientGetIdentity
and virNetServerClientSetIdentity, adding a new method
virNetServerClientSetAuth.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This patch introduces support for LXC specific public APIs. In
common with what was done for QEMU, this creates a libvirt_lxc.so
library and libvirt/libvirt-lxc.h header file.
The actual APIs are
int virDomainLxcOpenNamespace(virDomainPtr domain,
int **fdlist,
unsigned int flags);
int virDomainLxcEnterNamespace(virDomainPtr domain,
unsigned int nfdlist,
int *fdlist,
unsigned int *noldfdlist,
int **oldfdlist,
unsigned int flags);
which provide a way to use the setns() system call to move the
calling process into the container's namespace. It is not
practical to write in a generically applicable manner. The
nearest that we could get to such an API would be an API which
allows to pass a command + argv to be executed inside a
container. Even if we had such a generic API, this LXC specific
API is still useful, because it allows the caller to maintain
the current process context, in particular any I/O streams they
have open.
NB the virDomainLxcEnterNamespace() API is special in that it
runs client side, so does not involve the internal driver API.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
