https://bugzilla.redhat.com/show_bug.cgi?id=1047577
When a client closes its connection to libvirtd early during
virConnectOpen, more specifically just after making
REMOTE_PROC_CONNECT_SUPPORTS_FEATURE call to check if
VIR_DRV_FEATURE_PROGRAM_KEEPALIVE is supported without even waiting for
the result, libvirtd may crash due to a race in keep-alive
initialization. Once receiving the REMOTE_PROC_CONNECT_SUPPORTS_FEATURE
call, the daemon's event loop delegates it to a worker thread. In case
the event loop detects EOF on the connection and calls
virNetServerClientClose before the worker thread starts to handle
REMOTE_PROC_CONNECT_SUPPORTS_FEATURE call, client->keepalive will be
disposed by the time virNetServerClientStartKeepAlive gets called from
remoteDispatchConnectSupportsFeature. Because the flow is common for
both authenticated and read-only connections, even unprivileged clients
may cause the daemon to crash.
To avoid the crash, virNetServerClientStartKeepAlive needs to check if
the connection is still open before starting keep-alive protocol.
Every libvirt release since 0.9.8 is affected by this bug.
The x509dname is only set inside a WITH_GNUTLS conditional, so
when used/check later on for NULL, Coverity detects this is not
possible. Added WITH_GNUTLS around uses to remove message
virNetSASLSessionClientStep logs the data that is going to be passed to
sasl_client_step as input data. However, it tries to log it as a string,
while there is no guarantee that this data is going to be nul-terminated.
This leads to this valgrind log:
==20938== Invalid read of size 1
==20938== at 0x8BDB08F: vfprintf (vfprintf.c:1635)
==20938== by 0x8C06DF2: vasprintf (vasprintf.c:62)
==20938== by 0x4CCEDF9: virVasprintfInternal (virstring.c:337)
==20938== by 0x4CA9516: virLogVMessage (virlog.c:842)
==20938== by 0x4CA939A: virLogMessage (virlog.c:778)
==20938== by 0x4E21E0D: virNetSASLSessionClientStep (virnetsaslcontext.c:458)
==20938== by 0x4DE47B8: remoteAuthSASL (remote_driver.c:4136)
==20938== by 0x4DE33AE: remoteAuthenticate (remote_driver.c:3635)
==20938== by 0x4DDBFAA: doRemoteOpen (remote_driver.c:832)
==20938== by 0x4DDC8BA: remoteConnectOpen (remote_driver.c:1027)
==20938== by 0x4D8595F: do_open (libvirt.c:1239)
==20938== by 0x4D863F3: virConnectOpenAuth (libvirt.c:1481)
==20938== by 0x12762B: vshReconnect (virsh.c:337)
==20938== by 0x12C9B0: vshInit (virsh.c:2470)
==20938== by 0x12E9A5: main (virsh.c:3338)
==20938== Address 0xe329ccd is 0 bytes after a block of size 141 alloc'd
==20938== at 0x4A081D4: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==20938== by 0x8CB91B4: xdr_array (xdr_array.c:94)
==20938== by 0x4E039C2: xdr_remote_auth_sasl_start_ret (remote_protocol.c:3134)
==20938== by 0x4E1F8AA: virNetMessageDecodePayload (virnetmessage.c:405)
==20938== by 0x4E119F5: virNetClientProgramCall (virnetclientprogram.c:377)
==20938== by 0x4DF8141: callFull (remote_driver.c:5794)
==20938== by 0x4DF821A: call (remote_driver.c:5816)
==20938== by 0x4DE46CF: remoteAuthSASL (remote_driver.c:4112)
==20938== by 0x4DE33AE: remoteAuthenticate (remote_driver.c:3635)
==20938== by 0x4DDBFAA: doRemoteOpen (remote_driver.c:832)
==20938== by 0x4DDC8BA: remoteConnectOpen (remote_driver.c:1027)
==20938== by 0x4D8595F: do_open (libvirt.c:1239)
==20938== by 0x4D863F3: virConnectOpenAuth (libvirt.c:1481)
==20938== by 0x12762B: vshReconnect (virsh.c:337)
==20938== by 0x12C9B0: vshInit (virsh.c:2470)
==20938== by 0x12E9A5: main (virsh.c:3338)
The array of sasl_callback_t callbacks which is passed to sasl_client_new()
must be kept alive as long as the created sasl_conn_t object is alive as
cyrus-sasl uses this structure internally for things like logging, so
the memory used for callbacks must only be freed after sasl_dispose() has
been called.
During testing of successful SASL logins with
virsh -c qemu+tls:///system list --all
I've been getting invalid read reports from valgrind
==9237== Invalid read of size 8
==9237== at 0x6E93B6F: _sasl_getcallback (common.c:1745)
==9237== by 0x6E95430: _sasl_log (common.c:1850)
==9237== by 0x16593D87: digestmd5_client_mech_dispose (digestmd5.c:4580)
==9237== by 0x6E91653: client_dispose (client.c:332)
==9237== by 0x6E9476A: sasl_dispose (common.c:851)
==9237== by 0x4E225A1: virNetSASLSessionDispose (virnetsaslcontext.c:678)
==9237== by 0x4CBC551: virObjectUnref (virobject.c:262)
==9237== by 0x4E254D1: virNetSocketDispose (virnetsocket.c:1042)
==9237== by 0x4CBC551: virObjectUnref (virobject.c:262)
==9237== by 0x4E2701C: virNetSocketEventFree (virnetsocket.c:1794)
==9237== by 0x4C965D3: virEventPollCleanupHandles (vireventpoll.c:583)
==9237== by 0x4C96987: virEventPollRunOnce (vireventpoll.c:652)
==9237== by 0x4C94730: virEventRunDefaultImpl (virevent.c:274)
==9237== by 0x12C7BA: vshEventLoop (virsh.c:2407)
==9237== by 0x4CD3D04: virThreadHelper (virthreadpthread.c:161)
==9237== by 0x7DAEF32: start_thread (pthread_create.c:309)
==9237== by 0x8C86EAC: clone (clone.S:111)
==9237== Address 0xe2d61b0 is 0 bytes inside a block of size 168 free'd
==9237== at 0x4A07577: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==9237== by 0x4C73827: virFree (viralloc.c:580)
==9237== by 0x4DE4BC7: remoteAuthSASL (remote_driver.c:4219)
==9237== by 0x4DE33D0: remoteAuthenticate (remote_driver.c:3639)
==9237== by 0x4DDBFAA: doRemoteOpen (remote_driver.c:832)
==9237== by 0x4DDC8DC: remoteConnectOpen (remote_driver.c:1031)
==9237== by 0x4D8595F: do_open (libvirt.c:1239)
==9237== by 0x4D863F3: virConnectOpenAuth (libvirt.c:1481)
==9237== by 0x12762B: vshReconnect (virsh.c:337)
==9237== by 0x12C9B0: vshInit (virsh.c:2470)
==9237== by 0x12E9A5: main (virsh.c:3338)
This commit changes virNetSASLSessionNewClient() to take ownership of the SASL
callbacks. Then we can free them in virNetSASLSessionDispose() after the corresponding
sasl_conn_t has been freed.
aa0f099 introduced a strict error checking for getsockopt and it
revealed that getting a peer credential of a socket on FreeBSD
didn't work. Libvirtd hits the error:
error : virNetSocketGetUNIXIdentity:1198 : Failed to get valid
client socket identity groups
SOL_SOCKET (0xffff) was used as a level of getsockopt for
LOCAL_PEERCRED, however, it was wrong. 0 is correct as well as
Mac OS X.
So for LOCAL_PEERCRED our options are SOL_LOCAL (if defined) or
0 on Mac OS X and FreeBSD. According to the fact, the patch
simplifies the code by removing ifdef __APPLE__.
I tested the patch on FreeBSD 8.4, 9.2 and 10.0-BETA1.
Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
With Mac OS X 10.9, xdrproc_t is no longer defined as:
typedef bool_t (*xdrproc_t)(XDR *, ...);
but instead as:
typdef bool_t (*xdrproc_t)(XDR *, void *, unsigned int);
For reference, Linux systems typically define it as:
typedef bool_t (*xdrproc_t)(XDR *, void *, ...);
The rationale explained in the header is that using a vararg is
incorrect and has a potential to change the ABI slightly do to compiler
optimizations taken and the undefined behavior. They decided
to specify the exact number of parameters and for compatibility with old
code decided to make the signature require 3 arguments. The third
argument is ignored for cases that its not used and its recommended to
supply a 0.
While LOCAL_PEERCRED on the BSDs does not return the pid information of
the peer, Mac OS X 10.8 added LOCAL_PEERPID to retrieve the pid so we
should use that when its available to get that information.
There are still two places where we are using 1bit width unsigned
integer to store a boolean. There's no real need for this and these
occurrences can be replaced with 'bool'.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Unconditional use of getenv is not secure in setuid env.
While not all libvirt code runs in a setuid env (since
much of it only exists inside libvirtd) this is not always
clear to developers. So make all the code paranoid, even
if it only ever runs inside libvirtd.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
This patch improves the error checking in the LOCAL_PEERCRED version
of virNetSocketGetUNIXIdentity, used by FreeBSD and Mac OSX.
1. The error return paths now correctly unlock the socket. This is
implemented in exactly the same way as the SO_PEERCRED version,
using "goto cleanup"
2. cr.cr_ngroups is initialised to -1, and cr.cr_ngroups is checked
for negative and overlarge values.
This means that if the getsockopt() call returns success but doesn't
actually update the xucred structure, this is now caught. This
happened previously when getsockopt was called with SOL_SOCKET
instead of SOL_LOCAL, prior to commit 5a468b3, and resulted in
random uids being accepted.
Signed-off-by: Eric Blake <eblake@redhat.com>
<...>
/* Size of message length field. Not counted in VIR_NET_MESSAGE_MAX
* and VIR_NET_MESSAGE_INITIAL.
*/
const VIR_NET_MESSAGE_LEN_MAX = 4;
</...>
However, msg->bufferLength includes the length word. The wrong checking
was introduced by commit e914dcfd.
* src/rpc/virnetmessage.c:
- Correct the checking in virNetMessageEncodePayloadRaw
- Use a new variable to track the new payload length in
virNetMessageEncodePayloadRaw
Since 5a468b38b6 we use SOL_LOCAL for the 2nd argument of getsockopt()
however Lion added the define SOL_LOCAL set to 0, which is the value to
the 2nd argument of getsockopt() for Unix sockets on Mac OS X. So
instead of using the define just pass 0 so we restore compatibility
with Snow Leopard and Leopard.
Reported at https://github.com/mxcl/homebrew/pull/23141
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.
This fixes the following error:
error : virGetUserEnt:703 : Failed to find user record for uid '32654'
'32654' (it's random and varies) comes from getsockopt with
LOCAL_PEERCRED option. getsockopt returns w/o error but seems
to not set any value to the buffer for uid.
For Mac OS X, LOCAL_PEERCRED has to be used with SOL_LOCAL level.
With SOL_LOCAL, getsockopt returns a correct uid.
Note that SOL_LOCAL can be found in
/System/Library/Frameworks/Kernel.framework/Versions/A/Headers/sys/un.h.
Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
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>
On some systems (linux, cygwin and gnukfreebsd) rpcgen generates files
which when compiling produces this warning:
remote/remote_protocol.c: In function 'xdr_remote_node_get_cpu_stats_ret':
remote/remote_protocol.c:530: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
Hence, on those systems we need to post-process the files by the
rpc/genprotocol.pl perl script. At the beginning of the script the OS is
detected via $^O perl variable. From my latest build on FreeBSD I see we
need to fix the code there too. On FreeBSD the variable contains
'freebsd' string:
http://perldoc.perl.org/perlport.html#PLATFORMS
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
While BSDs don't support process creation timestamp information via
PEERCRED for Unix sockets, we need to actually initialize the value
because it is used by the libvirt code.
To allow creation of a virNetSocketPtr instance from a pre-opened
socketpair FD, add a virNetSocketNewConnectSockFD method.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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>
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>
The VIR_FREE() macro will cast away any const-ness. This masked a
number of places where we passed a 'const char *' string to
VIR_FREE. Fortunately in all of these cases, the variable was not
in fact const data, but a heap allocated string. Fix all the
variable declarations to reflect this.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The gendispatch.pl script puts comments at the top of files
it creates, saying that it auto-generated them. Also include
the name of the source data file which it reads when doing
the auto-generation.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Coverity complained about the usage of the uninitialized cacerts in the
event(s) that "access(certFile, R_OK)" and/or "access(cacertFile, R_OK)"
fail the for loop used to fill in the certs will have indeterminate data
as well as the possibility that both failures would result in the
gnutls_x509_crt_deinit() call having a similar fate.
Initializing cacerts only would resolve the issue; however, it still
would leave the indeterminate action, so rather add a parameter to
the virNetTLSContextLoadCACertListFromFile() to pass the max size rather
then overloading the returned count parameter. If the the call is never
made, then we won't go through the for loops referencing the empty
cacerts
So that app developers / admins know what access control checks
are performed for each API, this patch extends the API docs
generator to include details of the ACLs for each.
The gendispatch.pl script is extended so that it generates
a simple XML describing ACL rules, eg.
<aclinfo>
...
<api name='virConnectNumOfDomains'>
<check object='connect' perm='search_domains'/>
<filter object='domain' perm='getattr'/>
</api>
<api name='virDomainAttachDeviceFlags'>
<check object='domain' perm='write'/>
<check object='domain' perm='save' flags='!VIR_DOMAIN_AFFECT_CONFIG|VIR_DOMAIN_AFFECT_LIVE'/>
<check object='domain' perm='save' flags='VIR_DOMAIN_AFFECT_CONFIG'/>
</api>
...
</aclinfo>
The newapi.xsl template loads the XML files containing the ACL
rules and generates a short block of HTML for each API describing
the parameter checks and return value filters (if any).
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The code added to validate CA certificates did not take into
account the possibility that the cacert.pem file can contain
multiple (concatenated) cert data blocks. Extend the code for
loading CA certs to use the gnutls APIs for loading cert lists.
Add test cases to check that multi-level trees of certs will
validate correctly.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This configuration knob lets user to set the length of queue of
connection requests waiting to be accept()-ed by the daemon. IOW, it
just controls the @backlog passed to listen:
int listen(int sockfd, int backlog);
Currently, even if max_client limit is hit, we accept() incoming
connection request, but close it immediately. This has disadvantage of
not using listen() queue. We should accept() only those clients we
know we can serve and let all other wait in the (limited) queue.
This patch enables the password authentication in the libssh2 connection
driver. There are a few benefits to this step:
1) Hosts with challenge response authentication will now be supported
with the libssh2 connection driver.
2) Credential for hosts can now be stored in the authentication
credential config file
The password authentication method wasn't used as there wasn't a
pleasant way to pass the password. This patch adds the option to use
virAuth util functions to request the password either from a config file
or uses the conf callback to request it from the user.
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>
Change the ACL filter functions to use a 'bool' return
type instead of a tri-state 'int' return type. The callers
of these functions don't want to distinguish 'auth failed'
from other errors.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Extend the 'gendispatch.pl' script to be able to generate
three new types of file.
- 'aclheader' - defines signatures of helper APIs for
doing authorization checks. There is one helper API
for each API requiring an auth check. Any @acl
annotations result in a method being generated with
a suffix of 'EnsureACL'. If the ACL check requires
examination of flags, an extra 'flags' param will be
present. Some examples
extern int virConnectBaselineCPUEnsureACL(void);
extern int virConnectDomainEventDeregisterEnsureACL(virDomainDefPtr domain);
extern int virDomainAttachDeviceFlagsEnsureACL(virDomainDefPtr domain, unsigned int flags);
Any @aclfilter annotations resuilt in a method being
generated with a suffix of 'CheckACL'.
extern int virConnectListAllDomainsCheckACL(virDomainDefPtr domain);
These are used for filtering individual objects from APIs
which return a list of objects
- 'aclbody' - defines the actual implementation of the
methods described above. This calls into the access
manager APIs. A complex example:
/* Returns: -1 on error (denied==error), 0 on allowed */
int virDomainAttachDeviceFlagsEnsureACL(virConnectPtr conn,
virDomainDefPtr domain,
unsigned int flags)
{
virAccessManagerPtr mgr;
int rv;
if (!(mgr = virAccessManagerGetDefault()))
return -1;
if ((rv = virAccessManagerCheckDomain(mgr,
conn->driver->name,
domain,
VIR_ACCESS_PERM_DOMAIN_WRITE)) <= 0) {
virObjectUnref(mgr);
if (rv == 0)
virReportError(VIR_ERR_ACCESS_DENIED, NULL);
return -1;
}
if (((flags & (VIR_DOMAIN_AFFECT_CONFIG|VIR_DOMAIN_AFFECT_LIVE)) == 0) &&
(rv = virAccessManagerCheckDomain(mgr,
conn->driver->name,
domain,
VIR_ACCESS_PERM_DOMAIN_SAVE)) <= 0) {
virObjectUnref(mgr);
if (rv == 0)
virReportError(VIR_ERR_ACCESS_DENIED, NULL);
return -1;
}
if (((flags & (VIR_DOMAIN_AFFECT_CONFIG)) == (VIR_DOMAIN_AFFECT_CONFIG)) &&
(rv = virAccessManagerCheckDomain(mgr,
conn->driver->name,
domain,
VIR_ACCESS_PERM_DOMAIN_SAVE)) <= 0) {
virObjectUnref(mgr);
if (rv == 0)
virReportError(VIR_ERR_ACCESS_DENIED, NULL);
return -1;
}
virObjectUnref(mgr);
return 0;
}
- 'aclsyms' - generates a linker script to export the
APIs to drivers. Some examples
virConnectBaselineCPUEnsureACL;
virConnectCompareCPUEnsureACL;
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce annotations to all RPC messages to declare what
access control checks are required. There are two new
annotations defined:
@acl: <object>:<permission>
@acl: <object>:<permission>:<flagname>
Declare the access control requirements for the API. May be repeated
multiple times, if multiple rules are required.
<object> is one of 'connect', 'domain', 'network', 'storagepool',
'interface', 'nodedev', 'secret'.
<permission> is one of the permissions in access/viraccessperm.h
<flagname> indicates the rule only applies if the named flag
is set in the API call
@aclfilter: <object>:<permission>
Declare an access control filter that will be applied to a list
of objects being returned by an API. This allows the returned
list to be filtered to only show those the user has permissions
against
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Compilation on cygwin failed due to a bug in the sasl headers
present on that platform (libsasl2-devel 2.1.26):
In file included from rpc/virnetserverclient.c:27:0:
/usr/include/sasl/sasl.h:230:38: error: expected declaration specifiers or '...' before 'size_t'
Upstream is aware of their bug:
https://bugzilla.cyrusimap.org/show_bug.cgi?id=3759
* src/rpc/virnetserverclient.c (includes): Ensure size_t is
defined before using sasl.h.
Signed-off-by: Eric Blake <eblake@redhat.com>
Bummer, I committed, then fixed a typo, then tested, and forgot to
amend the commit before pushing 7d21d6b6.
* src/rpc/virnettlscontext.c (includes): Use correct spelling.
Building with gnutls 3.2.0 (such as shipped with current cygwin) fails
with:
rpc/virnettlscontext.c: In function 'virNetTLSSessionGetKeySize':
rpc/virnettlscontext.c:1358:5: error: implicit declaration of function 'gnutls_cipher_get_key_size' [-Wimplicit-function-declaration]
Yeah, it's stupid that gnutls broke API by moving their declaration
into a new header without including that header from the old one,
but it's easy enough to work around, all without breaking on gnutls
1.4.1 (hello RHEL 5) that lacked the new header.
* configure.ac (gnutls): Check for <gnutls/crypto.h>.
* src/rpc/virnettlscontext.c (includes): Include additional header.
Signed-off-by: Eric Blake <eblake@redhat.com>
Only a few cases are allowed:
1) The expression is empty for "for" loop, E.g.
for (i = 0; ; i++)
2) An empty statement
while (write(statuswrite, &status, 1) == -1 &&
errno == EINTR)
; /* empty */
3) ";" is inside double-quote, I.e, as part of const string. E.g.
vshPrint(ctl, "a ; b ; cd;\n");
The "for" loop in src/rpc/virnettlscontext.c is the special case,
1) applies for it, so change it together in this patch.
These all existed before virfile.c was created, and for some reason
weren't moved.
This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.
This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.
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>
There are various methods named "virXXXXSecurityContext",
which are specific to SELinux. Rename them all to
"virXXXXSELinuxContext". They will still raise errors at
runtime if SELinux is not compiled in
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
