When running setuid, we must be careful about what env vars
we allow commands to inherit from us. Replace the
virCommandAddEnvPass function with two new ones which do
filtering
virCommandAddEnvPassAllowSUID
virCommandAddEnvPassBlockSUID
And make virCommandAddEnvPassCommon use the appropriate
ones
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 9b8f307c6a)
Conflicts:
src/qemu/qemu_command.c
In Fedora 20, libvirt_lxc crashes immediately at startup with a
trace
#0 0x00007f0cddb653ec in free () from /lib64/libc.so.6
#1 0x00007f0ce0e16f4a in virFree (ptrptr=ptrptr@entry=0x7f0ce1830058) at util/viralloc.c:580
#2 0x00007f0ce0e2764b in virResetError (err=0x7f0ce1830030) at util/virerror.c:354
#3 0x00007f0ce0e27a5a in virResetLastError () at util/virerror.c:387
#4 0x00007f0ce0e28858 in virEventRegisterDefaultImpl () at util/virevent.c:233
#5 0x00007f0ce0db47c6 in main (argc=11, argv=0x7fff4596c328) at lxc/lxc_controller.c:2352
Normally virInitialize calls virErrorInitialize and
virThreadInitialize, but we don't link to libvirt.so
in libvirt_lxc, and nor did we ever call the error
or thread initializers.
I have absolutely no idea how this has ever worked, let alone
what caused it to stop working in Fedora 20.
In addition not all code paths from virLogSetFromEnv will
ensure virLogInitialize is called correctly, which is another
possible crash scenario.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 97973ebb7a)
The log message regex has been
[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{3}\+[0-9]{4}: [0-9]+: debug|info|warning|error :
The precedence of '|' is high though, so this is equivalent to matching
[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{3}\+[0-9]{4}: [0-9]+: debug
Or
info
Or
warning
Or
error :
Which is clearly not what it should have done. This caused the code to
skip over things which are not log messages. The solution is to simply
add brackets.
A test case is also added to validate correctness.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 5787f0b95e)
Many people will not want the setuid virt-login-shell binary
installed by default, so move it into a separate sub-RPM
named libvirt-login-shell. This RPM is only generated if
LXC is enabled
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 8adc92694f)
'make rpm' failed if ~/.rpmmacros contains '%_without_lxc 1',
which simulates the case of not having lxc available.
RPM build errors:
File not found: /home/eblake/rpmbuild/BUILDROOT/libvirt-1.1.1-1.fc19.x86_64/etc/libvirt/virt-login-shell.conf
File not found by glob: /home/eblake/rpmbuild/BUILDROOT/libvirt-1.1.1-1.fc19.x86_64/usr/share/man/man1/virt-login-shell.1*
File not found: /home/eblake/rpmbuild/BUILDROOT/libvirt-1.1.1-1.fc19.x86_64/usr/bin/virt-login-shell
make: *** [rpm] Error 1
Reported by Dan Berrange.
* libvirt.spec.in: Mark virt-login-shell as conditional on lxc.
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit d42906fd00)
The virt-login-shell binary shouldn't need to execute programs
relying on $PATH, but just in case set a fixed $PATH value
of /bin:/usr/bin
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit d665003da1)
Commit d76227be added functions virDomainCreateWithFiles and
virDomainCreateXMLWithFiles, but there was a little piece missing in
python bindings. This patch fixes proper passing of file descriptors
in the overwrites of these functions.
On systems where gnutls uses libgcrypt, I'm seeing the following
build failure
libvirt.c:314: error: variable 'virTLSThreadImpl' has initializer but incomplete type
libvirt.c:319: error: 'GCRY_THREAD_OPTION_PTHREAD' undeclared here (not in a function)
...
Fix by undefining WITH_GNUTLS_GCRYPT in config-post.h
After commit 3e2f27e1, I've noticed build failures of virt-login-shell
when libapparmor-devel is installed on the build host
CCLD virt-login-shell
../src/.libs/libvirt-setuid-rpc-client.a(libvirt_setuid_rpc_client_la-vircommand.o):
In function `virExec':
/home/jfehlig/virt/upstream/libvirt/src/util/vircommand.c:653: undefined
reference to `aa_change_profile'
collect2: error: ld returned 1 exit status
I was about to commit an easy fix under the build-breaker rule
(build-fix-1.patch), but thought to extend the notion of SECDRIVER_LIBS
to SECDRIVER_CFLAGS, and use both throughout src/Makefile.am where it
makes sense (build-fix-2.patch).
Should I just stick with the simple fix, or is something along the lines
of patch 2 preferred?
Regards,
Jim
>From a0f35945f3127ab70d051101037e821b1759b4bb Mon Sep 17 00:00:00 2001
From: Jim Fehlig <jfehlig@suse.com>
Date: Mon, 21 Oct 2013 15:30:02 -0600
Subject: [PATCH] build: fix virt-login-shell build with apparmor
With libapparmor-devel installed, virt-login-shell fails to link
CCLD virt-login-shell
../src/.libs/libvirt-setuid-rpc-client.a(libvirt_setuid_rpc_client_la-vircommand.o): In function `virExec':
/home/jfehlig/virt/upstream/libvirt/src/util/vircommand.c:653: undefined reference to `aa_change_profile'
collect2: error: ld returned 1 exit status
Fix by linking libvirt_setuid_rpc_client with previously determined
SECDRIVER_LIBS in src/Makefile.am. While at it, introduce SECDRIVER_CFLAGS
and use both throughout src/Makefile.am where it makes sense.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Conflicts:
src/Makefile.am: Context
The libvirt.so library has far too many library deps to allow
linking against it from setuid programs. Those libraries can
do stuff in __attribute__((constructor) functions which is
not setuid safe.
The virt-login-shell needs to link directly against individual
files that it uses, with all library deps turned off except
for libxml2 and libselinux.
Create a libvirt-setuid-rpc-client.la library which is linked
to by virt-login-shell. A config-post.h file allows this library
to disable all external deps except libselinux and libxml2.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 3e2f27e13b)
We don't want to inherit any FDs in the new namespace
except for the stdio FDs. Explicitly close them all,
just in case some do not have the close-on-exec flag
set.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit b7fcc799ad)
We must not allow file/syslog/journald log outputs when running
setuid since they can be abused to do bad things. In particular
the 'file' output can be used to overwrite files.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 8c3586ea75)
Care must be taken accessing env variables when running
setuid. Introduce a virGetEnvAllowSUID for env vars which
are safe to use in a setuid environment, and another
virGetEnvBlockSUID for vars which are not safe. Also add
a virIsSUID helper method for any other non-env var code
to use.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit ae53e5d10e)
The virConnectDomainXMLToNative API should require 'connect:write'
not 'connect:read', since it will trigger execution of the QEMU
binaries listed in the XML.
Also make virConnectDomainXMLFromNative API require a full
read-write connection and 'connect:write' permission. Although the
current impl doesn't trigger execution of QEMU, we should not
rely on that impl detail from an API permissioning POV.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 57687fd6bf)
Introduced by 7b87a3
When I quit the process which only register VIR_DOMAIN_EVENT_ID_REBOOT,
I got error like:
"libvirt: XML-RPC error : internal error: domain event 0 not registered".
Then I add the following code, it fixed.
Signed-off-by: Zhou Yimin <zhouyimin@huawei.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit 9712c2510e)
Introduced by commit 3f029fb531 the RPM build
was broken due to a missing LXC textcase.
Signed-off-by: Daniel Hansel <daniel.hansel@linux.vnet.ibm.com>
(cherry picked from commit 6285c17f79)
Since 76b644c when the support for RAM filesystems was introduced,
libvirt accepted the following XML:
<source usage='1024' unit='KiB'/>
This was parsed correctly and internally stored in bytes, but it
was formatted as (with an extra 's'):
<source usage='1024' units='KiB'/>
When read again, this was treated as if the units were missing,
meaning libvirt was unable to parse its own XML correctly.
The usage attribute was documented as being in KiB, but it was not
scaled if the unit was missing. Transient domains still worked,
because this was balanced by an extra 'k' in the mount options.
This patch:
Changes the parser to use 'units' instead of 'unit', as the latter
was never documented (fixing persistent domains) and some programs
(libvirt-glib, libvirt-sandbox) already parse the 'units' attribute.
Removes the extra 'k' from the tmpfs mount options, which is needed
because now we parse our own XML correctly.
Changes the default input unit to KiB to match documentation, fixing:
https://bugzilla.redhat.com/show_bug.cgi?id=1015689
(cherry picked from commit 3f029fb531)
After freeing the bitmap pointer, it must set the pointer to NULL.
This will avoid any other use of the freed memory of the bitmap pointer.
https://bugzilla.redhat.com/show_bug.cgi?id=1006710
Signed-off-by: Liuji (Jeremy) <jeremy.liu@huawei.com>
(cherry picked from commit ef5d51d491)
https://bugzilla.redhat.com/show_bug.cgi?id=1008619
1,003 bytes in 1 blocks are definitely lost in loss record 599 of 635
==404== by 0x50728A7: virBufferAddChar (virbuffer.c:185)
==404== by 0x50BC466: virSystemdEscapeName (virsystemd.c:67)
==404== by 0x50BC6B2: virSystemdMakeSliceName (virsystemd.c:108)
==404== by 0x50BC870: virSystemdCreateMachine (virsystemd.c:169)
==404== by 0x5078267: virCgroupNewMachine (vircgroup.c:1498)
(cherry picked from commit 09b48562aa)
https://bugzilla.redhat.com/show_bug.cgi?id=1006864
Commit 38ab1225 changed the default value of ret from true to false but
forgot to set ret = true when job is NONE. Thus, virsh domjobinfo
returned 1 when there was no job running for a domain but it used to
(and should) return 0 in this case.
(cherry picked from commit f084caae7c)
Commit 27e81517a8 set the payload size to 256 KB, which is
actually the max packet size, including the size of the header.
Reduce this by VIR_NET_MESSAGE_HEADER_MAX (24) and set
VIR_NET_MESSAGE_LEGACY_PAYLOAD_MAX to 262120, which was the original
value before increasing the limit in commit eb635de1fe.
(cherry picked from commit 609eb987c6)
The libvirtd server pushes data out to clients. It does not
know what protocol version the client might have, so must be
conservative and use the old payload limits. ie send no more
than 256kb of data per packet.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 27e81517a8)
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>
(cherry picked from commit 8294aa0c17)
Since the wait is done during migration (still inside
QEMU_ASYNC_JOB_MIGRATION_OUT), the code should enter the monitor as such
in order to prohibit all other jobs from interfering in the meantime.
This patch fixes bug #1009886 in which qemuDomainGetBlockInfo was
waiting on the monitor condition and after GetSpiceMigrationStatus
mangled its internal data, the daemon crashed.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1009886
(cherry picked from commit 484cc3217b)
The fix for CVE-2013-4311 had a pre-requisite enhancement
to the identity code
commit db7a5688c0
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Thu Aug 22 16:00:01 2013 +0100
Also store user & group ID values in virIdentity
This had a typo which caused the group ID to overwrite the
user ID string. This meant any checks using this would have
the wrong ID value. This only affected the ACL code, not the
initial polkit auth. It also leaked memory.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit e4697b92ab)
After commit 8aecd35126 it'll detect
that a required option is not defined and it will assert and exit with:
virsh.c:1364: vshCommandOpt: Assertion `valid->name' failed.
Problem has been latent since commit ed23b106.
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit fe64499dd1)
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>
(cherry picked from commit e7f400a110)
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>
(cherry picked from commit 922b7fda77)
The polkit access driver will want to use the process start
time field. This was already set for network identities, but
not for the system identity.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit e65667c0c6)
Future improvements to the polkit code will require access to
the numeric user ID, not merely user name.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit db7a5688c0)
Bother those kernel developers. In the latest rawhide, kernel
and glibc have now been unified so that <netinet/in.h> and
<linux/in6.h> no longer clash; but <linux/if_bridge.h> is still
not self-contained. Because of the latest header change, the
build is failing with:
checking for linux/param.h... no
configure: error: You must install kernel-headers in order to compile libvirt with QEMU or LXC support
with details:
In file included from conftest.c:561:0:
/usr/include/linux/in6.h:71:18: error: field 'flr_dst' has incomplete type
struct in6_addr flr_dst;
We need a workaround to avoid our workaround :)
* configure.ac (NETINET_LINUX_WORKAROUND): New test.
* src/util/virnetdevbridge.c (includes): Use it.
Signed-off-by: Eric Blake <eblake@redhat.com>
(cherry picked from commit e62e0094dc)
When virBufferError is ok in cmdAttachDisk, the latter
should 'goto cleanup', instead of returning a false to
prevent memory leaking.
Signed-off-by: Eric Blake <eblake@redhat.com>
Since virtlockd is only built when libvirtd is built, we should
not install its auxiliary files unconditionally. This solves
two failures. 1. 'make distcheck' complains:
rm -f Makefile
ERROR: files left in build directory after distclean:
./src/virtlockd.8
2. './autobuild.sh' complains:
Checking for unpackaged file(s): /usr/lib/rpm/check-files
/home/eblake/rpmbuild/BUILDROOT/mingw-libvirt-1.1.1-1.fc19.eblake1377879911.x86_64
error: Installed (but unpackaged) file(s) found:
/usr/i686-w64-mingw32/sys-root/mingw/etc/libvirt/virtlockd.conf
/usr/i686-w64-mingw32/sys-root/mingw/share/augeas/lenses/tests/test_virtlockd.aug
/usr/i686-w64-mingw32/sys-root/mingw/share/augeas/lenses/virtlockd.aug
/usr/i686-w64-mingw32/sys-root/mingw/share/man/man8/virtlockd.8
/usr/x86_64-w64-mingw32/sys-root/mingw/etc/libvirt/virtlockd.conf
/usr/x86_64-w64-mingw32/sys-root/mingw/share/augeas/lenses/tests/test_virtlockd.aug
/usr/x86_64-w64-mingw32/sys-root/mingw/share/augeas/lenses/virtlockd.aug
/usr/x86_64-w64-mingw32/sys-root/mingw/share/man/man8/virtlockd.8
* src/Makefile.am (CLEANFILES): Add virtlockd.8.
(man8_MANS, conf_DATA, augeas_DATA, augeastest_DATA): Only install
virtlockd files when daemon is built.
Signed-off-by: Eric Blake <eblake@redhat.com>
'make distcheck' was failing with:
make[3]: Entering directory `/home/eblake/libvirt-tmp2/libvirt-1.1.1/_build/docs'
perl ../../docs/genaclperms.pl ../../src/access/viraccessperm.h > ../../docs/aclperms.htmlinc
/bin/sh: ../../docs/aclperms.htmlinc: Permission denied
when simulating the case of a user doing a VPATH build from a
read-only source tree. The culprit? BUILT_SOURCES are _always_
built, and so must NOT be built into srcdir and need not be part
of the tarball. On the other hand, shipped files must never
depend on files in the builddir. While it would be possible to
fix the problem by generating aclperms.htmlinc into builddir,
we then have the problem that we ship acl.html - we'd have to
rejigger a lot of things to not ship pre-built html. So this
patch goes the other direction - we don't need BUILT_SOURCES,
but instead ensure that we have proper dependencies so that
all files in srcdir are up-to-date at the time the tarball is
created. And because we ship html files in the tarball, that
implies we don't expect users to be able to rebuild them, so
we must not clean any files that would trigger a rebuild except
under the maintainer rules.
* docs/Makefile.am (BUILT_SOURCES): Delete.
(CLEANFILES): Downgrade aclperms.htmlinc cleanup...
(maintainer-clean-local): ...and move hvsupport.html.in...
(MAINTAINERCLEANFILES): ...to a maintainer action.
(hvsupport.html.in): Write into srcdir.
(hvsupport.html): Ensure files are built in order.
(aclperms.htmlinc): Honor silent make.
(EXTRA_DIST): Ship aclperms.htmlinc.
Signed-off-by: Eric Blake <eblake@redhat.com>
With the 1.1.1 tarball, if a user does 'make && make distcheck',
things pass, but if they do 'make distcheck' after 'make clean',
there is an odd failure:
GEN ../../docs/devhelp/index.html
I/O error : Permission denied
I/O error : Permission denied
runtime error: file ../../docs/devhelp/devhelp.xsl line 43 element document
xsltDocumentElem: unable to save to ../../docs/devhelp/libvirt-virterror.html
I/O error : Permission denied
I/O error : Permission denied
This implies that the rules for 'make dist' are missing a
dependency - the generated documentation needs to be up-to-date
before creating the tarball, or else the tarball will be missing
files, where the end user will end up trying to rebuild files in
srcdir, and that fails when srcdir is read-only.
1.1.1 plus this patch now works without issues (other issues have
crept in to 1.1.2-rc1 that prevent 'make distcheck' from working,
but those will be cleaned up in later patches).
* docs/Makefile.am (dist-local): New dependency.
Signed-off-by: Eric Blake <eblake@redhat.com>
I noticed from an ./autobuild.sh run that we were installing a
virt-login-shell.exe binary when cross-building for mingw,
even though such a binary is necessarily worthless since the
code depends on lxc which is a Linux-only concept.
* tools/Makefile.am (conf_DATA, bin_PROGRAMS, dist_man1_MANS):
Make virt-login-shell installation conditional.
Signed-off-by: Eric Blake <eblake@redhat.com>
vhost only works in KVM mode at the moment, and is infact compiled
out if the emulator is built for non-native architecture. While it
may work at some point in the future for plain qemu, for now it's
just noise on the command line (and which contributes to arm cli
breakage).
Ubuntu libdbus.so links with -Bsymbolic-functions, which means
that we can only LD_PRELOAD functions that we directly call.
Functions which libdbus.so calls internally can not be replaced.
Thus we cannot use dbus_message_new_error or dbus_message_new_method_return
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
FreeBSD 10 recently changed their definition of RAND_MAX, to try
and cover the fact that their evenly distributed results of rand()
really are a smaller range than a full power of 2. As a result,
I did some investigation, and learned:
1. POSIX requires random() to be evenly distributed across exactly
31 bits. glibc also guarantees this for rand(), but the two are
unrelated, and POSIX only associates RAND_MAX with rand().
Avoiding RAND_MAX altogether thus avoids a build failure on
FreeBSD 10.
2. Concatenating random bits from a PRNG will NOT provide uniform
coverage over the larger value UNLESS the period of the original
PRNG is at least as large as the number of bits being concatenated.
Simple example: suppose that RAND_MAX were 1 with a period of 2**1
(which means that the PRNG merely alternates between 0 and 1).
Concatenating two successive rand() calls would then invariably
result in 01 or 10, which is a rather non-uniform distribution
(00 and 11 are impossible) and an even worse period (2**0, since
our second attempt will get the same number as our first attempt).
But a RAND_MAX of 1 with a period of 2**2 (alternating between
0, 1, 1, 0) provides sane coverage of all four values, if properly
tempered. (Back-to-back calls would still only see half the values
if we don't do some tempering). We therefore want to guarantee a
period of at least 2**64, preferably larger (as a tempering factor);
POSIX only makes this guarantee for random() with 256 bytes of info.
* src/util/virrandom.c (virRandomBits): Use constants that are
accurate for the PRNG we are using, not an unrelated PRNG.
(randomState): Ensure the period of our PRNG exceeds our usage.
Signed-off-by: Eric Blake <eblake@redhat.com>
Commit 29fe5d7 (released in 1.1.1) introduced a latent problem
for any caller of virSecurityManagerSetProcessLabel and where
the domain already had a uid:gid label to be parsed. Such a
setup would collect the list of supplementary groups during
virSecurityManagerPreFork, but then ignores that information,
and thus fails to call setgroups() to adjust the supplementary
groups of the process.
Upstream does not use virSecurityManagerSetProcessLabel for
qemu (it uses virSecurityManagerSetChildProcessLabel instead),
so this problem remained latent until backporting the initial
commit into v0.10.2-maint (commit c061ff5, released in 0.10.2.7),
where virSecurityManagerSetChildProcessLabel has not been
backported. As a result of using a different code path in the
backport, attempts to start a qemu domain that runs as qemu:qemu
will end up with supplementary groups unchanged from the libvirtd
parent process, rather than the desired supplementary groups of
the qemu user. This can lead to failure to start a domain
(typical Fedora setup assigns user 107 'qemu' to both group 107
'qemu' and group 36 'kvm', so a disk image that is only readable
under kvm group rights is locked out). Worse, it is a security
hole (the qemu process will inherit supplemental group rights
from the parent libvirtd process, which means it has access
rights to files owned by group 0 even when such files should
not normally be visible to user qemu).
LXC does not use the DAC security driver, so it is not vulnerable
at this time. Still, it is better to plug the latent hole on
the master branch first, before cherry-picking it to the only
vulnerable branch v0.10.2-maint.
* src/security/security_dac.c (virSecurityDACGetIds): Always populate
groups and ngroups, rather than only when no label is parsed.
Signed-off-by: Eric Blake <eblake@redhat.com>
The use of <> is a security issue for RPC parameters, since a
malicious client can set a huge array length causing arbitrary
memory allocation in the daemon.
It is also a robustness issue for RPC return values, because if
the stream is corrupted, it can cause the client to also allocate
arbitrary memory.
Use a syntax-check rule to prohibit any use of <>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
