This patch resolves CVE-2013-0170:
https://bugzilla.redhat.com/show_bug.cgi?id=893450
When reading and dispatching of a message failed the message was freed
but wasn't removed from the message queue.
After that when the connection was about to be closed the pointer for
the message was still present in the queue and it was passed to
virNetMessageFree which tried to call the callback function from an
uninitialized pointer.
This patch removes the message from the queue before it's freed.
* rpc/virnetserverclient.c: virNetServerClientDispatchRead:
- avoid use after free of RPC messages
(cherry picked from commit 46532e3e8e)
Fix for CVE-2012-4423.
When generating RPC protocol messages, it's strictly needed to have a
continuous line of numbers or RPC messages. However in case anyone
tries backporting some functionality and will skip a number, there is
a possibility to make the daemon segfault with newer virsh (version of
the library, rpc call, etc.) even unintentionally.
The problem is that the skipped numbers will get func filled with
NULLs, but there is no check whether these are set before the daemon
tries to run them. This patch very simply enhances one check and fixes
that.
(cherry picked from commit b7ff9e6960)
First 'poll' can't return EWOULDBLOCK, and second, we're checking errno
so far away from the poll() call that we've probably already trashed the
original errno value.
(cherry picked from commit 5d490603a6)
In addition to keepalive responses, we also need to send keepalive
requests from client IO loop to properly detect dead connection in case
a libvirt API is called from the main loop, which prevents any timers to
be called.
(cherry picked from commit 4d971dc7ef)
We don't need to add or remove filters when client object is already
locked anymore. There's no reason to keep the *Locked variants of those
APIs.
(cherry picked from commit d9ad416698)
The previous commit removed the only usage of ``all'' parameter in
virKeepAliveStopInternal, which was actually the only reason for having
virKeepAliveStopInternal. This effectively reverts most of commit
6446a9e20c.
(cherry picked from commit 0ec514b359)
When a libvirt API is called from the main event loop (which seems to be
common in event-based glib apps), the client IO loop would properly
handle keepalive requests sent by a server but will not actually send
them because the main event loop is blocked with the API. This patch
gets rid of response timer and the thread which is processing keepalive
requests is also responsible for queueing responses for delivery.
(cherry picked from commit bb85f2298e)
Add virKeepAliveTimeout and virKeepAliveTrigger APIs that can be used to
set poll timeouts and trigger keepalive timer. virKeepAliveTrigger
checks if it is called to early and does nothing in that case.
(cherry picked from commit 28c75382b0)
The code that needs to be run every keepalive interval of inactivity was
only called from a timer and thus from the main event loop. We will need
to call the code directly from another place.
(cherry picked from commit a2ba868632)
As we never drop non-blocking calls, the return value that used to
indicate a call was dropped is no longer needed.
(cherry picked from commit ca9b13e373)
As non-blocking calls are no longer dropped, we don't really need to
care that much about their fate and wait for the thread with the buck
to process them. If another thread has the buck, we can just push a
non-blocking call to the queue and be done with it.
(cherry picked from commit ef392614aa)
So far, we were dropping non-blocking calls whenever sending them would
block. In case a client is sending lots of stream calls (which are not
supposed to generate any reply), the assumption that having other calls
in a queue is sufficient to get a reply from the server doesn't work. I
tried to fix this in b1e374a7ac but
failed and reverted that commit.
With this patch, non-blocking calls are never dropped (unless the
connection is being closed) and will always be sent.
(cherry picked from commit 78602c4e83)
Normally, when every call has a thread associated with it, the thread
may get the buck and be in charge of sending all calls until its own
call is done. When we introduced non-blocking calls, we had to add
special handling of new non-blocking calls. This patch uses event loop
to send data if there is no thread to get the buck so that any
non-blocking calls left in the queue are properly sent without having to
handle them specially. It also avoids adding even more cruft to client
IO loop in the following patches.
With this change in, non-blocking calls may see unpredictable delays in
delivery when the client has no event loop registered. However, the only
non-blocking calls we have are keepalives and we already require event
loop for them, which makes this a non-issue until someone introduces new
non-blocking calls.
(cherry picked from commit 9e747e5c50)
The docs for virConnectSetKeepAlive() advertise that this function
should be able to disable keepalives on negative or zero interval time.
This patch removes the check that prohibited this and adds code to
disable keepalives on negative/zero interval.
* src/libvirt.c: virConnectSetKeepAlive(): - remove check for negative
values
* src/rpc/virnetclient.c
* src/rpc/virnetclient.h: - add virNetClientKeepAliveStop() to disable
keepalive messages
* src/remote/remote_driver.c: remoteSetKeepAlive(): -add ability to
disable keepalives
(cherry picked from commit 6446a9e20c)
Commit 32a9aac switched libvirt to use the XDG base directories
to locate most of its data/config. In particular, the per-user socket
for qemu:///session is now stored in the XDG runtime directory.
This directory is located by looking at the XDG_RUNTIME_DIR environment
variable, with a fallback to ~/.cache/libvirt if this variable is not
set.
When the daemon is autospawned because a client application wants
to use qemu:///session, the daemon is ran in a clean environment
which does not contain XDG_RUNTIME_DIR. It will create its socket
in ~/.cache/libvirt. If the client application has XDG_RUNTIME_DIR
set, it will not look for the socket in the fallback place, and will
fail to connect to the autospawned daemon.
This patch adds XDG_RUNTIME_DIR to the daemon environment before
auto-starting it. I've done this in virNetSocketForkDaemon rather
than in virCommandAddEnvPassCommon as I wasn't sure we want to pass
these variables to other commands libvirt spawns. XDG_CACHE_HOME
and XDG_CONFIG_HOME are also added to the daemon env as it makes use
of those as well.
(cherry picked from commit efe6c80211)
The stream lock is unlocked twice instead of being locked and then
unlocked. Probably a typo.
(cherry picked from commit 107f51b69c)
Conflicts:
AUTHORS
When you try to connect to a socket in the abstract namespace,
the error will be ECONNREFUSED for a non-listening daemon. With
the non-abstract namespace though, you instead get ENOENT. Add
a check for this extra errno when auto-spawning the daemon
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 54c4d9d90b)
This reverts commit b1e374a7ac, which was
rather bad since I failed to consider all sides of the issue. The main
things I didn't consider properly are:
- a thread which sends a non-blocking call waits for the thread with
the buck to process the call
- the code doesn't expect non-blocking calls to remain in the queue
unless they were already partially sent
Thus, the reverted patch actually breaks more than what it fixes and
clients (which may even be libvirtd during p2p migrations) will likely
end up in a deadlock.
(cherry picked from commit 63643f67ab)
Currently, non-blocking calls are either sent immediately or discarded
in case sending would block. This was implemented based on the
assumption that the non-blocking keepalive call is not needed as there
are other calls in the queue which would keep the connection alive.
However, if those calls are no-reply calls (such as those carrying
stream data), the remote party knows the connection is alive but since
we don't get any reply from it, we think the connection is dead.
This is most visible in tunnelled migration. If it happens to be longer
than keepalive timeout (30s by default), it may be unexpectedly aborted
because the connection is considered to be dead.
With this patch, we only discard non-blocking calls when the last call
with a thread is completed and thus there is no thread left to keep
sending the remaining non-blocking calls.
POSIX says that sa_sigaction is only safe to use if sa_flags
includes SA_SIGINFO; conversely, sa_handler is only safe to
use when flags excludes that bit. Gnulib doesn't guarantee
an implementation of SA_SIGINFO, but does guarantee that
if SA_SIGINFO is undefined, we can safely define it to 0 as
long as we don't dereference the 2nd or 3rd argument of
any handler otherwise registered via sa_sigaction.
Based on a report by Wen Congyang.
* src/rpc/virnetserver.c (SA_SIGINFO): Stub for mingw.
(virNetServerSignalHandler): Avoid bogus dereference.
(virNetServerFatalSignal, virNetServerNew): Set flags properly.
(virNetServerAddSignalHandler): Drop unneeded #ifdef.
The code is splattered with a mix of
sizeof foo
sizeof (foo)
sizeof(foo)
Standardize on sizeof(foo) and add a syntax check rule to
enforce it
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit 5d4b0c4c80 tried to fix certain classes of VPATH builds,
but was too limited. In particular, Guannan Ren reported:
> For example: The libvirt source code resides in /home/testuser,
> I make dist in /tmp/buildvpath, the XDR routine .c file will
> include full path of the header file like:
>
> #include "/home/testuser/src/rpc/virnetprotocol.h"
> #include "internal.h"
> #include <arpa/inet.h>
>
> If we distribute the tarball to another machine to compile,
> it will report error as follows:
>
> rpc/virnetprotocol.c:7:59: fatal error:
> /home/testuser/src/rpc/virnetprotocol.h: No such file or directory
* src/rpc/genprotocol.pl: Fix more include lines.
On 64-bit platforms, unsigned long and unsigned long long are
identical, so we don't have to worry about overflow checks.
On 32-bit platforms, anywhere we narrow unsigned long long back
to unsigned long, we have to worry about overflow; it's easier
to do this in one place by having most of the code use the same
or wider types, and only doing the narrowing at the last minute.
Therefore, the memory set commands remain unsigned long, and
the memory get command now centralizes the overflow check into
libvirt.c, so that drivers don't have to repeat the work.
This also fixes a bug where xen returned the wrong value on
failure (most APIs return -1 on failure, but getMaxMemory
must return 0 on failure).
* src/driver.h (virDrvDomainGetMaxMemory): Use long long.
* src/libvirt.c (virDomainGetMaxMemory): Raise overflow.
* src/test/test_driver.c (testGetMaxMemory): Fix driver.
* src/rpc/gendispatch.pl (name_to_ProcName): Likewise.
* src/xen/xen_hypervisor.c (xenHypervisorGetMaxMemory): Likewise.
* src/xen/xen_driver.c (xenUnifiedDomainGetMaxMemory): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xend_internal.h (xenDaemonDomainGetMaxMemory):
Likewise.
* src/xen/xm_internal.c (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xm_internal.h (xenXMDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.c (xenStoreDomainGetMaxMemory): Likewise.
* src/xen/xs_internal.h (xenStoreDomainGetMaxMemory): Likewise.
* src/xenapi/xenapi_driver.c (xenapiDomainGetMaxMemory):
Likewise.
* src/esx/esx_driver.c (esxDomainGetMaxMemory): Likewise.
* src/libxl/libxl_driver.c (libxlDomainGetMaxMemory): Likewise.
* src/qemu/qemu_driver.c (qemudDomainGetMaxMemory): Likewise.
* src/lxc/lxc_driver.c (lxcDomainGetMaxMemory): Likewise.
* src/uml/uml_driver.c (umlDomainGetMaxMemory): Likewise.
A multi-threaded client with event loop may crash if one of its threads
closes a connection while event loop is in the middle of sending
keep-alive message (either request or response). The right place for it
is inside virNetClientIOEventLoop() between poll() and
virNetClientLock(). We should only close a connection directly if no-one
is using it and defer the closing to the last user otherwise. So far we
only did so if the close was initiated by keep-alive timeout.
Nuke the last vestiges of printing pid_t values with the wrong
types, at least in code compiled on mingw64. There may be other
places, but for now they are only compiled on systems where the
existing %d doesn't trigger gcc warnings.
* src/rpc/virnetsocket.c (virNetSocketNew): Use %lld and casting,
rather than assuming any particular int type for pid_t.
* src/util/command.c (virCommandRunAsync, virPidWait)
(virPidAbort): Likewise.
(verify): Drop a now stale assertion.
Our HACKING discourages use of malloc and free, for at least
a couple of years now. But we weren't enforcing it, until now :)
For now, I've exempted python and tests, and will clean those up
in subsequent patches. Examples should be permanently exempt,
since anyone copying our examples won't have use of our
internal-only memory.h via libvirt_util.la.
* cfg.mk (sc_prohibit_raw_allocation): New rule.
(exclude_file_name_regexp--sc_prohibit_raw_allocation): and
exemptions.
* src/cpu/cpu.c (cpuDataFree): Avoid false positive.
* src/conf/network_conf.c (virNetworkDNSSrvDefParseXML): Fix
offenders.
* src/libxl/libxl_conf.c (libxlMakeDomBuildInfo, libxlMakeVfb)
(libxlMakeDeviceModelInfo): Likewise.
* src/rpc/virnetmessage.c (virNetMessageSaveError): Likewise.
* tools/virsh.c (_vshMalloc, _vshCalloc): Likewise.
Qemu is adding the ability to do a partial rebase. That is, given:
base <- intermediate <- current
virDomainBlockPull will produce:
current
but qemu now has the ability to leave base in the chain, to produce:
base <- current
Note that current qemu can only do a forward merge, and only with
the current image as the destination, which is fully described by
this API without flags. But in the future, it may be possible to
enhance this API for additional scenarios by using flags:
Merging the current image back into a previous image (that is,
undoing a live snapshot), could be done by passing base as the
destination and flags with a bit requesting a backward merge.
Merging any other part of the image chain, whether forwards (the
backing image contents are pulled into the newer file) or backwards
(the deltas recorded in the newer file are merged back into the
backing file), could also be done by passing a new flag that says
that base should be treated as an XML snippet rather than an
absolute path name, where the XML could then supply the additional
instructions of which part of the image chain is being merged into
any other part.
* include/libvirt/libvirt.h.in (virDomainBlockRebase): New
declaration.
* src/libvirt.c (virDomainBlockRebase): Implement it.
* src/libvirt_public.syms (LIBVIRT_0.9.10): Export it.
* src/driver.h (virDrvDomainBlockRebase): New driver callback.
* src/rpc/gendispatch.pl (long_legacy): Add exemption.
* docs/apibuild.py (long_legacy_functions): Likewise.
This API allows a domain to be put into one of S# ACPI states.
Currently, S3 and S4 are supported. These states are shared
with virNodeSuspendForDuration.
However, for now we don't support any duration other than zero.
The same apply for flags.
The RPC generator transforms methods matching certain
patterns like 'id' or 'uuid', etc but does not anchor
its matches to the end of the word. So if a method
contains 'id' in the middle (eg virIdentity) then the
RPC generator munges that.
* src/rpc/gendispatch.pl: Anchor matches
To avoid a namespace clash with forthcoming identity APIs,
rename the virNet*GetLocalIdentity() APIs to have the form
virNet*GetUNIXIdentity()
* daemon/remote.c, src/libvirt_private.syms: Update
for renamed APIs
* src/rpc/virnetserverclient.c, src/rpc/virnetserverclient.h,
src/rpc/virnetsocket.c, src/rpc/virnetsocket.h: s/LocalIdentity/UNIXIdentity/
If client stream does not have any data to sink and neither received
EOF, a dummy packet is sent to the daemon signalising client is ready to
sink some data. However, after we added event loop to client a race may
occur:
Thread 1 calls virNetClientStreamRecvPacket and since no data are cached
nor stream has EOF, it decides to send dummy packet to server which will
sent some data in turn. However, during this decision and actual message
exchange with server -
Thread 2 receives last stream data from server. Therefore an EOF is set
on stream and if there is a call waiting (which is not yet) it is woken
up. However, Thread 1 haven't sent anything so far, so there is no call
to be woken up. So this thread sent dummy packet to daemon, which
ignores that as no stream is associated with such packet and therefore
no reply will ever come.
This race causes client to hang indefinitely.
The RPC code had several latent memory leaks and an attempt to
free the wrong string, but thankfully nothing triggered them
(blkiotune was the only one returning a string, and always as
the last parameter). Also, our cleanups for rpcgen ended up
nuking a line of code that renders VIR_TYPED_PARAM_INT broken,
because it was the only use of 'i' in a function, even though
it was a member usage rather than a standalone declaration.
* daemon/remote.c (remoteSerializeTypedParameters): Free the
correct array element.
(remoteDispatchDomainGetSchedulerParameters)
(remoteDispatchDomainGetSchedulerParametersFlags)
(remoteDispatchDomainBlockStatsFlags)
(remoteDispatchDomainGetMemoryParameters): Don't leak strings.
* src/rpc/genprotocol.pl: Don't nuke member-usage of 'buf' or 'i'.
When one thread passes the buck to another thread, it uses
virCondSignal to wake up the target thread. The variable
'haveTheBuck' is not updated in a race-free manner when
this occurs. The current thread sets it to false, and the
woken up thread sets it to true. There is a window where
a 3rd thread can come in and grab the buck.
Even if this didn't lead to crashes & deadlocks, this would
still result in unfairness in the buckpassing algorithm.
A better solution is to *never* set haveTheBuck to false
when we're passing the buck. Only set it to false when there
is no further thread waiting for the buck.
* src/rpc/virnetclient.c: Only set haveTheBuck to false
if no thread is waiting
Commit fd06692544 tried to fix
a race condition in
commit fa9595003d
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Fri Nov 11 15:28:41 2011 +0000
Explicitly track whether the buck is held in remote client
Unfortunately there is a second race condition whereby the
event loop can trigger due to incoming data to read. Revert
this fix, so a complete fix for the problem can be cleanly
applied
* src/rpc/virnetclient.c: Revert fd06692544
Currently if you try to connect to a local libvirtd when
libvirtd is not in $PATH, you'll get an error
error: internal error invalid use of command API
This is because remoteFindDaemonPath() returns NULL, which
causes us to pass NULL into virNetSocketConnectUNIX which
in turn causes us to pass NULL into virCommandNewArgList.
Adding missing error checks improves this to
error: internal error Unable to locate libvirtd daemon in $PATH
* src/remote/remote_driver.c: Report error if libvirtd
cannot be found
* src/rpc/virnetsocket.c: Report error if caller requested
spawning of daemon, but provided no binary path
https://bugzilla.redhat.com/show_bug.cgi?id=648855 mentioned a
misuse of 'an' where 'a' is proper; that has since been fixed,
but a search found other problems (some were a spelling error for
'and', while most were fixed by 'a').
* daemon/stream.c: Fix grammar.
* src/conf/domain_conf.c: Likewise.
* src/conf/domain_event.c: Likewise.
* src/esx/esx_driver.c: Likewise.
* src/esx/esx_vi.c: Likewise.
* src/rpc/virnetclient.c: Likewise.
* src/rpc/virnetserverprogram.c: Likewise.
* src/storage/storage_backend_fs.c: Likewise.
* src/util/conf.c: Likewise.
* src/util/dnsmasq.c: Likewise.
* src/util/iptables.c: Likewise.
* src/xen/xen_hypervisor.c: Likewise.
* src/xen/xend_internal.c: Likewise.
* src/xen/xs_internal.c: Likewise.
* tools/virsh.c: Likewise.
The RPC fixups needed on Linux are also needed on cygwin, and
worked without further tweaking to the list of fixups. Also,
unlike BSD, Cygwin exports 'struct ifreq', but unlike Linux,
Cygwin lacks the ioctls that we were using 'struct ifreq' to
access. This patch allows compilation under cygwin.
* src/rpc/genprotocol.pl: Also perform fixups on cygwin.
* src/util/virnetdev.c (HAVE_STRUCT_IFREQ): Also require AF_PACKET
definition.
* src/util/virnetdevbridge.c (virNetDevSetupControlFull): Only
compile if SIOCBRADDBR works.
Originaly, the code checked if another client is the queue and infered
ownership of the buck from that. Commit fa9595003d
added a separate variable to track the buck. That caused, that a new
call might enter claiming it has the buck, while another thread was
signalled to take the buck. This ends in two threads claiming they hold
the buck and entering poll(). This happens due to a race on waking up
threads on the client lock mutex.
This caused multi-threaded clients to hang, most prominently visible and
reproducible on python based clients, like virt-manager.
This patch causes threads, that have been signalled to take the buck to
re-check if buck is held by another thread.
Detected by Coverity. Leak introduced in commit 673adba.
Two separate bugs here:
1. call was not freed on all error paths
2. virCondDestroy was called even if virCondInit failed
Signed-off-by: Alex Jia <ajia@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
When another thread was dispatching while we wanted to send a
non-blocking call, we correctly queued the call and woke up the thread
but the thread just threw the call away since it forgot to recheck if
its socket was writable.
When spawning an ssh connection, the environment variables
DISPLAY, SSH_ASKPASS, ... are passed. However XAUTHORITY,
which is necessary if the .Xauthority is in a non default
place, was not passed.
Signed-off-by: Christian Franke <nobody@nowhere.ws>
