The _cmp_bytes variable added by commit "bea60dd ui/vnc: fix potential
memory corruption issues" can become negative. Result is (possibly
exploitable) memory corruption. Reason for that is it uses the stride
instead of bytes per scanline to apply limits.
For the server surface is is actually fine. vnc creates that itself,
there is never any padding and thus scanline length always equals stride.
For the guest surface scanline length and stride are typically identical
too, but it doesn't has to be that way. So add and use a new variable
(guest_ll) for the guest scanline length. Also rename min_stride to
line_bytes to make more clear what it actually is. Finally sprinkle
in an assert() to make sure we never use a negative _cmp_bytes again.
Reported-by: 范祚至(库特) <zuozhi.fzz@alibaba-inc.com>
Reviewed-by: P J P <ppandit@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
If vnc's password is configured, it will leak memory
which cipher variable pointed on every vnc connection.
Cc: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Message-Id: <1437556133-11268-1-git-send-email-arei.gonglei@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 800567a61 updated the code to the generic crypto API
and mixed up encrypt and decrypt functions in
procotol_client_auth_vnc.
(Used to be: deskey(key, EN0) which encrypts, and was
changed to qcrypto_cipher_decrypt in 800567a61.)
Changed it to qcrypto_cipher_encrypt now.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Switch the VNC server over to use the generic cipher API, this
allows it to use the pluggable DES implementations, instead of
being hardcoded to use QEMU's built-in impl.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-11-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove the direct use of gnutls for hash processing in the
websockets code, in favour of using the crypto APIs. This
allows the websockets code to be built unconditionally
removing countless conditional checks from the VNC code.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-9-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To prepare for a generic internal cipher API, move the
built-in D3DES implementation into the crypto/ directory.
This is not in fact a normal D3DES implementation, it is
D3DES with double & triple length modes removed, and the
key bytes in reversed bit order. IOW it is crippled
specifically for the "benefit" of RFB, so call the new
files desrfb.c instead of d3des.c to make it clear that
it isn't a generally useful impl.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-4-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In particular, don't include it into headers.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
These macros expand into error class enumeration constant, comma,
string. Unclean. Has been that way since commit 13f59ae.
The error class is always ERROR_CLASS_GENERIC_ERROR since the previous
commit.
Clean up as follows:
* Prepend every use of a QERR_ macro by ERROR_CLASS_GENERIC_ERROR, and
delete it from the QERR_ macro. No change after preprocessing.
* Rewrite error_set(ERROR_CLASS_GENERIC_ERROR, ...) into
error_setg(...). Again, no change after preprocessing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
qerror_report_err() is a transitional interface to help with
converting existing monitor commands to QMP. It should not be used
elsewhere.
The only remaining user in qemu-option.c is qemu_opts_parse(). Is it
used in QMP context? If not, we can simply replace
qerror_report_err() by error_report_err().
The uses in qemu-img.c, qemu-io.c, qemu-nbd.c and under tests/ are
clearly not in QMP context.
The uses in vl.c aren't either, because the only QMP command handlers
there are qmp_query_status() and qmp_query_machines(), and they don't
call it.
Remaining uses:
* drive_def(): Command line -drive and such, HMP drive_add and pci_add
* hmp_chardev_add(): HMP chardev-add
* monitor_parse_command(): HMP core
* tmp_config_parse(): Command line -tpmdev
* net_host_device_add(): HMP host_net_add
* net_client_parse(): Command line -net and -netdev
* qemu_global_option(): Command line -global
* vnc_parse_func(): Command line -display, -vnc, default display, HMP
change, QMP change. Bummer.
* qemu_pci_hot_add_nic(): HMP pci_add
* usb_net_init(): Command line -usbdevice, HMP usb_add
Propagate errors through qemu_opts_parse(). Create a convenience
function qemu_opts_parse_noisily() that passes errors to
error_report_err(). Switch all non-QMP users outside tests to it.
That leaves vnc_parse_func(). Propagate errors through it. Since I'm
touching it anyway, rename it to vnc_parse().
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Retain the function value for now, to permit selective conversion of
its callers.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Before:
qemu-system-x86_64: -display vnc=unix:/root/foo.sock: Failed to start VNC server on `(null)': Failed to bind socket to /root/foo.sock: Permission denied
After:
qemu-system-x86_64: -display vnc=unix:/root/foo.sock: Failed to start VNC server: Failed to bind socket to /root/foo.sock: Permission denied
Rather than tweak the string possibly show unix: value as well,
just drop the explicit display reporting. We already get the cli
string in the error message, that should be sufficient.
Signed-off-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The qemu_acl_init() function has long since stopped being able
to return NULL, since g_malloc will abort on OOM. As such the
checks for NULL were unreachable code.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Commit v2.2.0-1530-ge556032 vnc: switch to inet_listen_opts
bypassed the use of inet_parse in inet_listen, making literal
IPv6 addresses enclosed in brackets fail:
qemu-kvm: -vnc [::1]:0: Failed to start VNC server on `(null)': address
resolution failed for [::1]:5900: Name or service not known
Strip the brackets to make it work again.
Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The previous change to the auth scheme handling guarantees we
can never have nested TLS sessions in the VNC websockets server.
Thus we can remove the separate gnutls_session instance.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
When TLS is required, the primary VNC server considers it to be
mandatory. ie the server admin decides whether or not TLS is used,
and the client has to comply with this decision. The websockets
server, however, treated it as optional, allowing non-TLS clients
to connect to a server which had setup TLS. Thus enabling websockets
lowers the security of the VNC server leaving the admin no way to
enforce use of TLS.
This removes the code that allows non-TLS fallback in the websockets
server, so that if TLS is requested for VNC it is now mandatory for
both the primary VNC server and the websockets VNC server.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The way the websockets TLS code was integrated into the VNC server
made it essentially useless. The only time that the websockets TLS
support could be used is if the primary VNC server had its existing
TLS support disabled. ie QEMU had to be launched with:
# qemu -vnc localhost:1,websockets=5902,x509=/path/to/certs
Note the absence of the 'tls' flag. This is already a bug, because
the docs indicate that 'x509' is ignored unless 'tls' is given.
If the primary VNC server had TLS turned on via the 'tls' flag,
then this prevented the websockets TLS support from being used,
because it activates the VeNCrypt auth which would have resulted
in TLS being run over a TLS session. Of course no websockets VNC
client supported VeNCrypt so in practice, since the browser clients
cannot setup a nested TLS session over the main HTTPS connection,
so it would not even get past auth.
This patch causes us to decide our auth scheme separately for the
main VNC server vs the websockets VNC server. We take account of
the fact that if TLS is enabled, then the websockets client will
use https, so setting up VeNCrypt is thus redundant as it would
lead to nested TLS sessions.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The vnc_display_open method is quite long and complex, so
move the VNC auth scheme decision logic into a separate
method for clarity.
Also update the comment to better describe what we are
trying to achieve.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
If the VNC server is built without tls, sasl or websocket support
and the user requests one of these features, they are just silently
ignored. This is bad because it means the VNC server ends up running
in a configuration that is less secure than the user asked for.
It also leads to an tangled mass of preprocessor conditionals when
configuring the VNC server.
This ensures that the tls, sasl & websocket options are always
processed and an error is reported back to the user if any of
them were disabled at build time.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Handling of VNC audio messages results in printfs to the console.
This is of no use to anyone in production, so should be using the
normal VNC_DEBUG macro instead.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Error classes are a leftover from the days of "rich" error objects.
New code should always use ERROR_CLASS_GENERIC_ERROR. Commit 1d0d59f
added a use of ERROR_CLASS_DEVICE_NOT_FOUND. Replace it.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
vs->lsock may equal to 0, modify the check condition,
avoid possible vs->lsock leak.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The 'x509verify' parameter is documented as taking a path to the
x509 certificates, ie the same syntax as the 'x509' parameter.
commit 4db14629c3
Author: Gerd Hoffmann <kraxel@redhat.com>
Date: Tue Sep 16 12:33:03 2014 +0200
vnc: switch to QemuOpts, allow multiple servers
caused a regression by turning 'x509verify' into a boolean
parameter instead. This breaks setup from libvirt and is not
consistent with the docs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Use inet_listen_opts instead of inet_listen. Allows us to drop some
pointless indirection: Format strings just to parse them again later on.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Nobody cares about those strings, they are only used to check whenever
the vnc server / websocket support is enabled or not. Add bools for
this and drop the strings.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
This way the generated id will be stored in -writeconfig cfg files.
Also we can make vnc_auto_assign_id() local to vnc.c.
Tested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
vnc_display_local_addr will not be called with an invalid display id.
Add assert() to silence coverity warning about a null pointer dereference.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
in case we send and update for a complete scanline increment
the y offset to avoid running to find_next_bit for that lines
twice.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Add new query vnc qmp command, for the lack of better ideas just name it
"query-vnc-servers". Changes over query-vnc:
* It returns a list of vnc servers, so multiple vnc server instances
are covered.
* Each vnc server returns a list of server sockets. Followup patch
will use that to also report websockets. In case we add support for
multiple server sockets server sockets (to better support ipv4+ipv6
dualstack) we can add them to the list too.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Also track the number of connections in "connecting" and "shared" state
(in addition to the "exclusive" state). Apply a configurable limit to
these connections.
The logic to apply the limit to connections in "shared" state is pretty
simple: When the limit is reached no new connections are allowed.
The logic to apply the limit to connections in "connecting" state (this
is the state you are in *before* successful authentication) is
slightly different: A new connect kicks out the oldest client which is
still in "connecting" state. This avoids a easy DoS by unauthenticated
users by simply opening connections until the limit is reached.
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds a display= parameter to the vnc options. This allows to
bind a vnc server instance to a specific display, allowing to create a
multiseat setup with a vnc server for each seat.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch switches vnc over to QemuOpts, and it (more or less
as side effect) allows multiple vnc server instances.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
In case the display id is "default" (which is the one you get if you
don't explicitly assign one) we keep the old name scheme, without
display, for backward compatibility reasons.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
DisplayState isn't used anywhere, drop it. Add the vnc server ID as
parameter instead, so it is possible to specify the server instance.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Replace with a vnc_displays list, so we can have multiple vnc server
instances. Add vnc_server_find function to lookup a display by id.
With no id supplied return the first vnc server, for backward
compatibility reasons.
It is not possible (yet) to actually create multiple vnc server
instances.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
At least all the ones I've tested. We make the assumption that
pixman is going to be better at conversion than we are.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[ kraxel: just hook up qemu_pixman_check_format ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
graphic_hw_update and vnc_refresh_server_surface aren't
need to do when no vnc client connected. It can reduce
lock contention, because vnc_refresh will hold global big
lock two millisecond every three seconds.
Signed-off-by: ChenLiang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
bits_per_pixel that are less than 8 could result in accessing
non-initialized buffers later in the code due to the expectation
that bytes_per_pixel value that is used to initialize these buffers is
never zero.
To fix this check that bits_per_pixel from the client is one of the
values that the rfb protocol specification allows.
This is CVE-2014-7815.
Signed-off-by: Petr Matousek <pmatouse@redhat.com>
[ kraxel: apply codestyle fix ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
