Commit Graph

26 Commits

Author SHA1 Message Date
Peter Wu 0ae0b069aa vnc: fix memleak of the "vnc-worker-output" name
Fixes repeated memory leaks of 18 bytes when using VNC:

    Direct leak of 831024 byte(s) in 46168 object(s) allocated from:
        ...
        #4 0x7f6d2f919bdd in g_strdup_vprintf glib/gstrfuncs.c:514
        #5 0x56085cdcf660 in buffer_init util/buffer.c:59
        #6 0x56085ca6a7ec in vnc_async_encoding_start ui/vnc-jobs.c:177
        #7 0x56085ca6b815 in vnc_worker_thread_loop ui/vnc-jobs.c:240

Fixes: 543b95801f ("vnc: attach names to buffers")
Cc: Gerd Hoffmann <kraxel@redhat.com>
CC: qemu-stable@nongnu.org
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20180807221830.3844-1-peter@lekensteyn.nl
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-08-24 08:40:10 +02:00
Gerd Hoffmann f31f9c1080 vnc: add magic cookie to VncState
Set magic cookie on initialization.  Clear on cleanup.  Sprinkle a bunch
of assert()s checking the cookie, to verify the pointer is valid.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20180507102254.12107-1-kraxel@redhat.com
2018-05-15 10:36:55 +02:00
Klim Kireev d49b87f0d1 vnc: fix segfault in closed connection handling
On one of our client's node, due to trying to read from closed ioc,
a segmentation fault occured. Corresponding backtrace:

0  object_get_class (obj=obj@entry=0x0)
1  qio_channel_readv_full (ioc=0x0, iov=0x7ffe55277180 ...
2  qio_channel_read (ioc=<optimized out> ...
3  vnc_client_read_buf (vs=vs@entry=0x55625f3c6000, ...
4  vnc_client_read_plain (vs=0x55625f3c6000)
5  vnc_client_read (vs=0x55625f3c6000)
6  vnc_client_io (ioc=<optimized out>, condition=G_IO_IN, ...
7  g_main_dispatch (context=0x556251568a50)
8  g_main_context_dispatch (context=context@entry=0x556251568a50)
9  glib_pollfds_poll ()
10 os_host_main_loop_wait (timeout=<optimized out>)
11 main_loop_wait (nonblocking=nonblocking@entry=0)
12 main_loop () at vl.c:1909
13 main (argc=<optimized out>, argv=<optimized out>, ...

Having analyzed the coredump, I understood that the reason is that
ioc_tag is reset on vnc_disconnect_start and ioc is cleaned
in vnc_disconnect_finish. Between these two events due to some
reasons the ioc_tag was set again and after vnc_disconnect_finish
the handler is running with freed ioc,
which led to the segmentation fault.

The patch checks vs->disconnecting in places where we call
qio_channel_add_watch and resets handler if disconnecting == TRUE
to prevent such an occurrence.

Signed-off-by: Klim Kireev <klim.kireev@virtuozzo.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20180207094844.21402-1-klim.kireev@virtuozzo.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-02-16 12:23:54 +01:00
Daniel P. Berrange ada8d2e436 ui: fix VNC client throttling when forced update is requested
The VNC server must throttle data sent to the client to prevent the 'output'
buffer size growing without bound, if the client stops reading data off the
socket (either maliciously or due to stalled/slow network connection).

The current throttling is very crude because it simply checks whether the
output buffer offset is zero. This check is disabled if the client has requested
a forced update, because we want to send these as soon as possible.

As a result, the VNC client can cause QEMU to allocate arbitrary amounts of RAM.
They can first start something in the guest that triggers lots of framebuffer
updates eg play a youtube video. Then repeatedly send full framebuffer update
requests, but never read data back from the server. This can easily make QEMU's
VNC server send buffer consume 100MB of RAM per second, until the OOM killer
starts reaping processes (hopefully the rogue QEMU process, but it might pick
others...).

To address this we make the throttling more intelligent, so we can throttle
full updates. When we get a forced update request, we keep track of exactly how
much data we put on the output buffer. We will not process a subsequent forced
update request until this data has been fully sent on the wire. We always allow
one forced update request to be in flight, regardless of what data is queued
for incremental updates or audio data. The slight complication is that we do
not initially know how much data an update will send, as this is done in the
background by the VNC job thread. So we must track the fact that the job thread
has an update pending, and not process any further updates until this job is
has been completed & put data on the output buffer.

This unbounded memory growth affects all VNC server configurations supported by
QEMU, with no workaround possible. The mitigating factor is that it can only be
triggered by a client that has authenticated with the VNC server, and who is
able to trigger a large quantity of framebuffer updates or audio samples from
the guest OS. Mostly they'll just succeed in getting the OOM killer to kill
their own QEMU process, but its possible other processes can get taken out as
collateral damage.

This is a more general variant of the similar unbounded memory usage flaw in
the websockets server, that was previously assigned CVE-2017-15268, and fixed
in 2.11 by:

  commit a7b20a8efa
  Author: Daniel P. Berrange <berrange@redhat.com>
  Date:   Mon Oct 9 14:43:42 2017 +0100

    io: monitor encoutput buffer size from websocket GSource

This new general memory usage flaw has been assigned CVE-2017-15124, and is
partially fixed by this patch.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20171218191228.31018-11-berrange@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2018-01-12 13:48:54 +01:00
Peter Maydell c3ff04b60d ui/vnc: Drop unused vnc_has_job() and vnc_jobs_clear()
The functions vnc_has_job() and vnc_jobs_clear() are
never used; remove them.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Message-id: 1486146260-8092-1-git-send-email-peter.maydell@linaro.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2017-02-08 14:59:36 +01:00
Peter Maydell e16f4c8770 ui: Clean up includes
Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1454089805-5470-2-git-send-email-peter.maydell@linaro.org
2016-02-04 17:01:04 +00:00
Daniel P. Berrange 04d2529da2 ui: convert VNC server to use QIOChannelSocket
The minimal first step conversion to use QIOChannelSocket
classes instead of directly using POSIX sockets API. This
will later be extended to also cover the TLS, SASL and
websockets code.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-12-18 15:02:11 +00:00
Peter Maydell c27e9014d5 vnc: buffer code improvements, bugfixes.
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJWShBCAAoJEEy22O7T6HE4/L4P/j2do44O18ni7OfloXQvCa5q
 xI21F/FqWZvpNVQnuhkFaBP8j9ggHIaKHJCMzQqSTs/ub+izKvsgFVWu5M9NAMPx
 OOhT20enigsBxP/WPrpjUknrMmjcnEXfYQfRhVREOZCkak95jfP8cLEAg1W81ehf
 /xS5TAJtGkxpxhQNpv94jXV5WdJmBYtKSUfUtHaEA2mgUeUrvUYlCQUUJrb23foG
 2LKGiv1GMqtNGHtl+uvBBc4XDdRrBR2iMgjjhj6IWniDCL2uxHojEN+Z23d1ldSK
 DXnNvoCVb5qzhSVVxJW34P0V2WJ8fClc0gvMWxtOvA4vLn/jnJw/Ig2MV1n4iQNu
 6vm3ZUUbz4f18eB63xy35AN4C63YgZ5xduGQ55HVMyMUtcyxkNv4SFA4NEY8Osj3
 Iy1TR+zXvdjH3d4K26J/s8/Lc1MVWlvGw6JzQn6gCF5x4ig8uKbA89S19skNw0Fe
 IXm5qHjUNNRwzG6/eGB1xpNz4O+yqGXfBAErsb0IbLBUdlweGLCZHvek2FCOUWiF
 7DY+dutFSW+nRjdOEKbRsHZL7ENB6vMzXFD3RH/EzWyvjveYl2yj2CshvHhBWxcx
 B4us35hQd7+KnkbcOQAcq5hxeXN9ZxLXjuOVB/3he+blH9uVPWo4BX6bQ71sXUpa
 kgIsPhzxCo+Bto/7P93F
 =oNDV
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/kraxel/tags/pull-vnc-20151116-1' into staging

vnc: buffer code improvements, bugfixes.

# gpg: Signature made Mon 16 Nov 2015 17:20:02 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-vnc-20151116-1:
  vnc: fix mismerge
  buffer: allow a buffer to shrink gracefully
  buffer: factor out buffer_adj_size
  buffer: factor out buffer_req_size
  vnc: recycle empty vs->output buffer
  vnc: fix local state init
  vnc: only alloc server surface with clients connected
  vnc: use vnc_{width,height} in vnc_set_area_dirty
  vnc: factor out vnc_update_server_surface
  vnc: add vnc_width+vnc_height helpers
  vnc: zap dead code
  vnc-jobs: move buffer reset, use new buffer move
  vnc: kill jobs queue buffer
  vnc: attach names to buffers
  buffer: add tracing
  buffer: add buffer_shrink
  buffer: add buffer_move
  buffer: add buffer_move_empty
  buffer: add buffer_init
  buffer: make the Buffer capacity increase in powers of two

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2015-11-17 12:34:07 +00:00
Markus Armbruster fedf0d35aa ui: Use g_new() & friends where that makes obvious sense
g_new(T, n) is neater than g_malloc(sizeof(T) * n).  It's also safer,
for two reasons.  One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.

This commit only touches allocations with size arguments of the form
sizeof(T).  Same Coccinelle semantic patch as in commit b45c03f.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-11-06 15:42:38 +03:00
Peter Lieven c3d6899c5e vnc: recycle empty vs->output buffer
If the vs->output buffer is empty it will be dropped
by the next qio_buffer_move_empty in vnc_jobs_consume_buffer
anyway. So reuse the allocated buffer from this buffer
in the worker thread where we otherwise would start with
an empty (unallocated buffer).

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-17-git-send-email-kraxel@redhat.com

[ added a comment describing the non-obvious optimization ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2015-11-05 09:09:31 +01:00
Gerd Hoffmann 2e0c90af0a vnc: fix local state init
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-16-git-send-email-kraxel@redhat.com
2015-11-05 09:09:27 +01:00
Gerd Hoffmann d90340115a vnc-jobs: move buffer reset, use new buffer move
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-10-git-send-email-kraxel@redhat.com
2015-11-05 09:08:59 +01:00
Gerd Hoffmann 8305f917c1 vnc: kill jobs queue buffer
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-9-git-send-email-kraxel@redhat.com
2015-11-05 09:08:56 +01:00
Gerd Hoffmann 543b95801f vnc: attach names to buffers
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-8-git-send-email-kraxel@redhat.com
2015-11-05 09:08:52 +01:00
Markus Armbruster a0b1a66ea3 Include monitor/monitor.h exactly where needed
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>
2015-06-22 18:20:41 +02:00
Thomas Huth 09526058d0 ui/vnc: Remove vnc_stop_worker_thread()
This function is not used anymore, let's remove it.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-03-10 08:15:33 +03:00
Peter Maydell fe6c53b4bb vnc dirty tracking optinizations.
various vnc bugfixes.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQIcBAABAgAGBQJTHbKaAAoJEEy22O7T6HE4zwAP/0Auz/T/Q+r3KQQfAgICFg4F
 wdWUQFi+M9+iub8tR+MAJLxJDGjyT3QQcYk7wyQTbttEHJawlhrHNFZYPlbsPOI1
 VuS/hATioUD815ch5gcuGt8yS7z9YfGwn84yopoge3L6SkW9x9jp/uXLvVe5WzJ1
 +5pGVVKH22aHG7kurrfGuqh1Uofj/GlPy6D5hX3DtLu1WPoTJN53ODwU35qR9j+o
 m1y1kDKN6KXICSDSzieLgSV4P6f4vu9zM3yiArK31tEWR+gBMH1lysoqYWIc+NCG
 R4QQZjDOYGIyXfCAPZJ0iV1wcoep2mPOxF0e+3WwXtBK0yRIFPEHwT5/geTpTsWK
 9+ERRflEYIx5evbw2+LHlW7AAeW7R8HhJggwp4UeWC9grjFNbS86JHsJDQ4Op84k
 oDtr11uG9z+GBCXDOLEe2/1WpPSTnd/K1bMW5x/AvDX8MiVrE67gmErL4GM9WOnC
 C4LRZnfmzqCN4hfBeMoEWuqIekI4Q/5+0f2WRBpWWU5KMV9W6CLR6c9HGI3E/1sx
 21DFzspK+97vG+T/LrmW0WKXTq3ll6H4QaoLDPccH4Pqy9x7FkgWXhWBPhWlTxsH
 Q+gvxW8XhspdyZnjLwovybo65o+JlXZ01eDLIINELr5Gx62MtWdnGUZqbdpH8V7P
 duCaAkU7tpjk9RtBFCN6
 =7t/O
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/kraxel/tags/pull-vnc-1' into staging

vnc dirty tracking optinizations.
various vnc bugfixes.

# gpg: Signature made Mon 10 Mar 2014 12:39:54 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-vnc-1:
  ui/vnc: disable adaptive update calculations if not needed
  ui/vnc: optimize setting in vnc_dpy_update()
  ui/vnc: optimize clearing in find_and_clear_dirty_height()
  ui/vnc: optimize dirty bitmap tracking
  ui/vnc: derive cmp_bytes from VNC_DIRTY_PIXELS_PER_BIT
  ui/vnc: introduce VNC_DIRTY_PIXELS_PER_BIT macro
  vnc: fix use-after-free in vnc_update_client_sync
  vnc: Fix qemu crashed when vnc client disconnect suddenly
  vnc: Fix tight_detect_smooth_image() for lossless case

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2014-03-11 10:53:17 +00:00
Gonglei (Arei) e3c1adf16e vnc: Fix qemu crashed when vnc client disconnect suddenly
Hi,

When I use RealVNC viewer client (http://www.realvnc.com/) to connect vnc server,
the client disconnect suddenly, and I click reconnect button immediately, then the Qemu crashed.

In the function vnc_worker_thread_loop, will call vnc_async_encoding_start
to set the local vs->output buffer by global queue's buffer. Then send rectangles to
the vnc client call function vnc_send_framebuffer_update. Finally, Under normal circumstances,
call vnc_async_encoding_end to set the global queue'buffer by the local vs->output conversely.

When the vnc client disconnect, the job->vs->csock will be set to -1. And the current prcoess
logic will goto disconnected partion without call function vnc_async_encoding_end.
But, the function vnc_send_framebuffer_update will call buffer_reserve, which
maybe call g_realloc reset the local vs's buffer, meaning the global queue's buffer is modified also.
If anyone use the original global queue's buffer memory will cause corruption and then crash qemu.

This patch assure the function vnc_async_encoding_end being called
even though the vnc client disconnect suddenly.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2014-03-10 12:35:04 +01:00
Dr. David Alan Gilbert 4900116e6f Add a 'name' parameter to qemu_thread_create
If enabled, set the thread name at creation (on GNU systems with
  pthread_set_np)
Fix up all the callers with a thread name

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2014-03-09 21:09:38 +02:00
Gerd Hoffmann d39fa6d86d vnc: stop using DisplayState
Rework DisplayStateListener callbacks to not use the DisplayState
any more.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2013-03-18 10:21:58 +01:00
Paolo Bonzini 1de7afc984 misc: move include files to include/qemu/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:32:39 +01:00
Blue Swirl ef84755ebb Merge branch 'trivial-patches' of git://github.com/stefanha/qemu
* 'trivial-patches' of git://github.com/stefanha/qemu:
  pc: Drop redundant test for ROM memory region
  exec: make some functions static
  target-ppc: make some functions static
  ppc: add missing static
  vnc: add missing static
  vl.c: add missing static
  target-sparc: make do_unaligned_access static
  m68k: Return semihosting errno values correctly
  cadence_uart: More debug information

Conflicts:
	target-m68k/m68k-semi.c
2012-11-03 12:55:05 +00:00
Blue Swirl 71a8cdeca0 vnc: add missing static
Add missing 'static' qualifiers.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-11-01 19:49:45 +01:00
Gerd Hoffmann 9f64916da2 pixman/vnc: use pixman images in vnc.
The vnc code uses *three* DisplaySurfaces:

First is the surface of the actual QemuConsole, usually the guest
screen, but could also be a text console (monitor/serial reachable via
Ctrl-Alt-<nr> keys).  This is left as-is.

Second is the current server's view of the screen content.  The vnc code
uses this to figure which parts of the guest screen did _really_ change
to reduce the amount of updates sent to the vnc clients.  It is also
used as data source when sending out the updates to the clients.  This
surface gets replaced by a pixman image.  The format changes too,
instead of using the guest screen format we'll use fixed 32bit rgb
framebuffer and convert the pixels on the fly when comparing and
updating the server framebuffer.

Third surface carries the format expected by the vnc client.  That isn't
used to store image data.  This surface is switched to PixelFormat and a
boolean for bigendian byte order.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2012-11-01 14:00:04 +01:00
Peter Maydell 11f6697861 ui/vnc-jobs.c: Fix minor typos in comments
Fix some minor typos/grammar errors in comments.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-10-19 10:42:01 +02:00
Daniel P. Berrange 2624bab836 Remove support for non-threaded VNC server
QEMU now has a fundamental requirement for pthreads, so there
is no compelling reason to retain support for the non-threaded
VNC server. Remove the --{enable,disable}-vnc-thread configure
arguments, and all CONFIG_VNC_THREAD conditionals

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-06-27 16:27:00 -05:00