Commit Graph

2297 Commits

Author SHA1 Message Date
Enrico Weigelt 442aec2219 include: move BUG_*() macros to separate header
Yet another step of uncluttering includes: move out the BUG_* macros
into a separate header, which then is included as-needed.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2024-02-15 23:33:46 +00:00
Enrico Weigelt, metux IT consult b3b86ae674 replace _X_INLINE by inline in internal static functions
Since xserver is compiled as C99, we just can use the `inline` keyword.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
2024-02-05 19:26:14 +00:00
Wanli Niu e62246641b dix: Fix segfault if CreateGC() failed in XaceHook()
CreateGC() allocates a new GC and then checks the resource access rights
with XaceHook().

If the call to XaceHook() fails (i.e. GC creation is not granted to the
client), CreateGC() exits early and calls FreeGC() to avoid leaking the
newly allocated GC.

If that happens, the screen's own CreateGC() has not yet been invoked,
and as a result the GC functions (GCfuncs) have not been set yet.

FreeGC() will invoke the funcs->DestroyClip() and the funcs->DestroyGC()
functions, but since those haven't been set, the Xserver will segfault
trying to call a NULL function.

To prevent that issue, make sure the GC's functions are initialized
prior to call them in FreeGC().

Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1625
Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>
2024-02-01 10:10:53 +01:00
Peter Hutterer 133e0d651c dix: fix valuator copy/paste error in the DeviceStateNotify event
Fixes 219c54b8a3
2024-01-22 21:24:58 +00:00
Peter Hutterer 26769aa71f dix: when disabling a master, float disabled slaved devices too
Disabling a master device floats all slave devices but we didn't do this
to already-disabled slave devices. As a result those devices kept their
reference to the master device resulting in access to already freed
memory if the master device was removed before the corresponding slave
device.

And to match this behavior, also forcibly reset that pointer during
CloseDownDevices().

Related to CVE-2024-21886, ZDI-CAN-22840
2024-01-16 09:24:31 +01:00
José Expósito bc1fdbe465 Xi: do not keep linked list pointer during recursion
The `DisableDevice()` function is called whenever an enabled device
is disabled and it moves the device from the `inputInfo.devices` linked
list to the `inputInfo.off_devices` linked list.

However, its link/unlink operation has an issue during the recursive
call to `DisableDevice()` due to the `prev` pointer pointing to a
removed device.

This issue leads to a length mismatch between the total number of
devices and the number of device in the list, leading to a heap
overflow and, possibly, to local privilege escalation.

Simplify the code that checked whether the device passed to
`DisableDevice()` was in `inputInfo.devices` or not and find the
previous device after the recursion.

CVE-2024-21886, ZDI-CAN-22840

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
2024-01-16 09:24:31 +01:00
Peter Hutterer 219c54b8a3 dix: fix DeviceStateNotify event calculation
The previous code only made sense if one considers buttons and keys to
be mutually exclusive on a device. That is not necessarily true, causing
a number of issues.

This function allocates and fills in the number of xEvents we need to
send the device state down the wire.  This is split across multiple
32-byte devices including one deviceStateNotify event and optional
deviceKeyStateNotify, deviceButtonStateNotify and (possibly multiple)
deviceValuator events.

The previous behavior would instead compose a sequence
of [state, buttonstate, state, keystate, valuator...]. This is not
protocol correct, and on top of that made the code extremely convoluted.

Fix this by streamlining: add both button and key into the deviceStateNotify
and then append the key state and button state, followed by the
valuators. Finally, the deviceValuator events contain up to 6 valuators
per event but we only ever sent through 3 at a time. Let's double that
troughput.

CVE-2024-0229, ZDI-CAN-22678

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
2024-01-16 09:24:01 +01:00
Peter Hutterer ece23be888 dix: Allocate sufficient xEvents for our DeviceStateNotify
If a device has both a button class and a key class and numButtons is
zero, we can get an OOB write due to event under-allocation.

This function seems to assume a device has either keys or buttons, not
both. It has two virtually identical code paths, both of which assume
they're applying to the first event in the sequence.

A device with both a key and button class triggered a logic bug - only
one xEvent was allocated but the deviceStateNotify pointer was pushed on
once per type. So effectively this logic code:

   int count = 1;
   if (button && nbuttons > 32) count++;
   if (key && nbuttons > 0) count++;
   if (key && nkeys > 32) count++; // this is basically always true
   // count is at 2 for our keys + zero button device

   ev = alloc(count * sizeof(xEvent));
   FixDeviceStateNotify(ev);
   if (button)
     FixDeviceStateNotify(ev++);
   if (key)
     FixDeviceStateNotify(ev++);   // santa drops into the wrong chimney here

If the device has more than 3 valuators, the OOB is pushed back - we're
off by one so it will happen when the last deviceValuator event is
written instead.

Fix this by allocating the maximum number of events we may allocate.
Note that the current behavior is not protocol-correct anyway, this
patch fixes only the allocation issue.

Note that this issue does not trigger if the device has at least one
button. While the server does not prevent a button class with zero
buttons, it is very unlikely.

CVE-2024-0229, ZDI-CAN-22678

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
2024-01-16 09:24:01 +01:00
Peter Hutterer 9e2ecb2af8 dix: allocate enough space for logical button maps
Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for
each logical button currently down. Since buttons can be arbitrarily mapped
to anything up to 255 make sure we have enough bits for the maximum mapping.

CVE-2023-6816, ZDI-CAN-22664, ZDI-CAN-22665

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
2024-01-16 09:23:47 +01:00
Peter Hutterer de0031eefd dix: initialize the XTest sendEventsProc for all devices
XTest requests lets the client specify a device ID, only if none
is specified do we fall back to the XTEST special device.
As of commit
  aa4074251 input: Add new hook DeviceSendEventsProc for XTEST
regular devices are no longer able to send XTest events because they
have no sendEventsProc set.

This caused issue #1574 and the crash was fixed with commit
  e820030de xtest: Check whether there is a sendEventsProc to call
but we still cannot send XTest events through a specific device.

Fix this by defaulting every device to the XTest send function and
punting it to the DDX (i.e. Xwayland) to override the devices as
necessary.

Fixes e820030de2
Fixes aa4074251f
2024-01-09 00:45:31 +00:00
Peter Hutterer d0b0137a95 Two whitespace fixes 2024-01-09 09:49:54 +10:00
Peter Hutterer 0a9f223eec dix: factor out the duplicate the RemoveDevice code paths
This is the same loop twice, once over inputInfo.devices and once over
inputInfo.off_devices, let's make both the same.
2024-01-09 09:49:54 +10:00
Peter Hutterer 2cee5fb36c test: fix various leaks in the tests 2024-01-09 09:49:54 +10:00
Peter Hutterer 373cd80081 dix: use valuator_mask_free() to free the last touches vmask
No functional effect since that one is just a free() call anyway.
2024-01-09 09:49:54 +10:00
Peter Hutterer 7aba2514b2 dix: don't allow for devices with 0 axes
This just makes the existing behavior explicit, previously we relied on
a malloc(numAxes * ...) to return NULL to error out.
2024-01-09 09:49:54 +10:00
Peter Hutterer 0c1a93d319 Xi: allocate enough XkbActions for our buttons
button->xkb_acts is supposed to be an array sufficiently large for all
our buttons, not just a single XkbActions struct. Allocating
insufficient memory here means when we memcpy() later in
XkbSetDeviceInfo we write into memory that wasn't ours to begin with,
leading to the usual security ooopsiedaisies.

CVE-2023-6377, ZDI-CAN-22412, ZDI-CAN-22413

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
2023-12-13 10:44:49 +10:00
Peter Hutterer 45009fb7f5 dix: clean up the GestureInfoRec on device close
Direct leak of 1080 byte(s) in 3 object(s) allocated from:
    #0 0x7f00a4ed8cc7 in calloc (/lib64/libasan.so.8+0xd8cc7) (BuildId: 6f17f87dc4c1aa9f9dde7c4856604c3a25ba4872)
    #1 0x59f740 in InitGestureClassDeviceStruct ../dix/devices.c:1692
    #2 0x418a0b in xwl_pointer_proc_pointer_gestures ../hw/xwayland/xwayland-input.c:325
    #3 0x598e5c in ActivateDevice ../dix/devices.c:578
    #4 0x420207 in init_pointer_gestures_device ../hw/xwayland/xwayland-input.c:1677
    #5 0x420bf1 in seat_handle_capabilities ../hw/xwayland/xwayland-input.c:1801
    #6 0x7f00a4145055 in ffi_call_unix64 (/lib64/libffi.so.8+0x9055) (BuildId: 308041eea4a8d89d9265d3c24b7261dfbe44a61e)

Acked-by: Olivier Fourdan <ofourdan@redhat.com>
2023-12-05 14:21:28 +10:00
Peter Hutterer 564ccf2ce9 mi: reset the PointerWindows reference on screen switch
PointerWindows[] keeps a reference to the last window our sprite
entered - changes are usually handled by CheckMotion().

If we switch between screens via XWarpPointer our
dev->spriteInfo->sprite->win is set to the new screen's root window.
If there's another window at the cursor location CheckMotion() will
trigger the right enter/leave events later. If there is not, it skips
that process and we never trigger LeaveWindow() - PointerWindows[] for
the device still refers to the previous window.

If that window is destroyed we have a dangling reference that will
eventually cause a use-after-free bug when checking the window hierarchy
later.

To trigger this, we require:
- two protocol screens
- XWarpPointer to the other screen's root window
- XDestroyWindow before entering any other window

This is a niche bug so we hack around it by making sure we reset the
PointerWindows[] entry so we cannot have a dangling pointer. This
doesn't handle Enter/Leave events correctly but the previous code didn't
either.

CVE-2023-5380, ZDI-CAN-21608

This vulnerability was discovered by:
Sri working with Trend Micro Zero Day Initiative

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Adam Jackson <ajax@redhat.com>
2023-10-25 00:37:47 +00:00
Alan Coopersmith d6b20f5e36 Remove "All rights reserved" from Oracle copyright notices
Oracle no longer includes this term in our copyright & license notices.

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
2023-02-25 09:40:41 -08:00
Yao Wei 7ce57e179b dix: Force update LEDs after device state update in EnableDevice
This is to make sure the hardware gets the device states regardless
whether the internal state has changed or not, to overcome situations
that device LEDs are out of sync e.g. switching between VTs.

Signed-off-by: Yao Wei (魏銘廷) <yao.wei@canonical.com>
2023-02-21 03:43:05 +00:00
Peter Hutterer d2158d4063 dix: fix wheel emulation lockup when a negative increment is set
The increment sign wasn't taking into account when checking if the next
value is past our current value. The result was that for negative
increments, we kept looping indefinitely, locking up the server.

Easiest to reproduce with the evdev driver which has a negative
increment on the y axis.

Fixes 0a22502c34
  dix: switch scroll button emulation to multiples of increment

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2023-02-20 15:11:23 +10:00
Peter Hutterer 0a22502c34 dix: switch scroll button emulation to multiples of increment
The current algorithm triggers a bug in Xwayland when two devices have
different granularity of scrolling. In Xwayland, the scroll increment is
1 and all physical devices scroll through the same (x)wayland pointer
device.

This may cause events to get lost when changing devices:
- mouse scrolls by full increment, current value is 1.0
  last scroll button was sent for valuator value 0.0,
  delta is 1.0 and we emulate a button event.
- touchpad scrolls by partial increment, current value is 1.3
  last scroll button was sent for valuator value 1.0, delta is 0.3
  and no button event is emulated
- mouse scrolls by full increment, current value is -0.7,
  last scroll button was sent for valuator value 1.0, delta is -0.7
  and no button event is emulated

Thus the wheel event appears to get lost. Xwayland cannot reliably
detect this case because we don't see the physical devices.

We can work around this by instead emulating buttons whenever we cross
a multiple of increment. However, this has a drawback:
high-resolution scroll devices can now trigger a button event storm by
jittering across the multiple of increment. e.g. in the example above
the touchpad moving from 1.3 to 1.0 would cause a click, despite this
being a third of an increment.

Fixes #1339

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Olivier Fourdan <ofourdan@redhat.com>
2023-02-16 10:25:16 +00:00
Peter Hutterer 6f0cd15155 dix: remove pointless "flexible" x/y axis mapping
storeLastValuators() takes the index in the mask for the x and y axis.
Completely pointless because any device that doesn't have x/y on 0 and
1, respectively, is going to break in fun ways anyway. And we only have
two callers two this function, both of which hardcode 0 and 1.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2023-02-16 10:25:16 +00:00
Olivier Fourdan e196535abb dix: Clear device sprite after free in AttachDevice()
The code in AttachDevice() may free the dev->spriteInfo->sprite under
some circumstances and later call GetCurrentRootWindow() which uses
the same dev->spriteInfo->sprite.

While it seems unlikely that this is actually an issue, considering the
cases where one or the other get called, it still makes the code look
suspicious.

Make sure to clear set dev->spriteInfo->sprite to NULL  immediately
after it's freed to avoid any confusion, even if only to clarify the
code.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1436
2023-02-09 23:54:11 +00:00
Mike Gorse 2ef5ef57bd dix: Use CopyPartialInternalEvent in EnqueueEvent
The event might be a DeviceEvent allocated on the stack, in
AccessXKeyboardEvent for instance. Fixes out-of-bounds read.

Signed-off-by: Mike Gorse <mgorse@suse.com>
2023-01-25 02:02:48 +00:00
Jeremy Huddleston Sequoia 16e7cdba48 rootless: Use screen_x and screen_y instead of pixmap pointer hacks
This updates rootless to treat pixmaps consistently with COMPOSITE,
using the screen_x and screen_y values rather than doing hacky math.

This will allow for proper bounds checking on a given PixmapRec.

Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
2023-01-20 17:10:54 +00:00
Peter Hutterer 412777664a Disallow byte-swapped clients by default
The X server swapping code is a huge attack surface, much of this code
is untested and prone to security issues. The use-case of byte-swapped
clients is very niche, so let's disable this by default and allow it
only when the respective config option or commandline flag is given.

For Xorg, this adds the ServerFlag "AllowByteSwappedClients" "on".
For all DDX, this adds the commandline options +byteswappedclients and
-byteswappedclients to enable or disable, respectively.

Fixes #1201

https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1029

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2023-01-06 11:59:37 +10:00
Peter Hutterer f69280ddcd dix: localize two variables
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2023-01-06 11:59:37 +10:00
Peter Hutterer a8c2e60d8d dix: remove unused PANORAMIX_DEBUG ifdef
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2023-01-06 11:59:37 +10:00
Peter Hutterer 73d6e888c6 Fix some indentation issues
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
2023-01-06 11:59:37 +10:00
Jeremy Huddleston Sequoia 3cb3024fea dix: Remove pScratchPixmap and other associated ABI changes
Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
2022-12-30 01:32:25 +00:00
Jeremy Huddleston Sequoia 6ee937b3be dix: Stop recycling scratch pixmaps
The minimal performance wins we gain by recycling pixmaps at this layer are
not worth the code complexity nor the interference with memory analysis
tools like malloc history, ASan, etc.

Signed-off-by: Jeremy Huddleston Sequoia <jeremyhu@apple.com>
2022-12-30 01:32:25 +00:00
Sultan Alsawaf 08183c66e8 pixmap: make PixmapDirtyCopyArea public
PixmapDirtyCopyArea() is about to be used outside of pixmap.c, so fix up
its interface by specifying the dirty area directly rather than passing a
`PixmapDirtyUpdatePtr`. This makes it easier to use outside of pixmap.c, as
the caller doesn't need to create a bulky PixmapDirtyUpdateRec to use this
function.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
2022-12-19 23:56:27 -08:00
Peter Hutterer 8f454b793e Xi: avoid integer truncation in length check of ProcXIChangeProperty
This fixes an OOB read and the resulting information disclosure.

Length calculation for the request was clipped to a 32-bit integer. With
the correct stuff->num_items value the expected request size was
truncated, passing the REQUEST_FIXED_SIZE check.

The server then proceeded with reading at least stuff->num_items bytes
(depending on stuff->format) from the request and stuffing whatever it
finds into the property. In the process it would also allocate at least
stuff->num_items bytes, i.e. 4GB.

The same bug exists in ProcChangeProperty and ProcXChangeDeviceProperty,
so let's fix that too.

CVE-2022-46344, ZDI-CAN 19405

This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Acked-by: Olivier Fourdan <ofourdan@redhat.com>
2022-12-14 11:02:40 +10:00
Michel Dänzer f778b56a74 dix: Skip more code in SetRootClip for ROOT_CLIP_INPUT_ONLY
Despite e957a2e5dd ("dix: Add hybrid full-size/empty-clip mode to
SetRootClip"), I was still seeing all X11 client windows flashing when
the root window size changes with rootless Xwayland (e.g. due to
hotplugging a monitor).

Skipping this code for ROOT_CLIP_INPUT_ONLY fixes the issue for me.
2022-09-12 10:51:05 +00:00
Alan Coopersmith 5cc24dbb4c dix: Use memcpy() instead of memmove() when buffers are known not to overlap
Most of these came from a mass bcopy() -> memmove() substitution in 1993
with a commit comment of "Ansification (changed bfuncs -> mfuncs)"

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
2022-08-29 21:10:51 +00:00
Olivier Fourdan 2efa6d6595 dix: Fix overzealous caching of ResourceClientBits()
Commit c7311654 cached the value of ResourceClientBits(), but that value
depends on the `MaxClients` value set either from the command line or
from the configuration file.

For the latter, a call to ResourceClientBits() is issued before the
configuration file is read, meaning that the cached value is from the
default, not from the maximum number of clients set in the configuration
file.

That obviously causes all sort of issues, including memory corruption
and crashes of the Xserver when reaching the default limit value.

To avoid that issue, also keep the LimitClient value, and recompute the
ilog2() value if that changes, as on startup when the value is set from
the the xorg.conf ServerFlags section.

v2: Drop the `cache == 0` test
    Rename cache vars

Fixes: c7311654 - dix: cache ResourceClientBits() value
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1310
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
2022-07-27 17:09:29 +02:00
Alan Coopersmith 6f9fce0360 Replace "the the" with a single "the" in docs & comments
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Martin Roukala <martin.roukala@mupuf.org>
2022-03-31 13:27:57 -07:00
Povilas Kanapickas 43e934a19f dix: Don't send touch end to clients that do async grab without touches
GTK3 menu widget creates a selection for touch and other events and
after receiving touch events creates an async grab that excludes touch
events. Unfortunately it relies on X server not sending the touch end
event in order to function properly. Sending touch end event will cause
it to think that the initiating touch ended and when it actually ends,
the ButtonRelease event will make it think that the menu should be
closed. As a result, the menu will be open only for the duration of the
touch making it useless.

This commit reverts f682e0563f.

Fixes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1255

Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
2022-02-12 15:26:30 +00:00
Povilas Kanapickas 1801fe0ac3 dix: Fix use after free in input device shutdown
This fixes access to freed heap memory via dev->master. E.g. when
running BarrierNotify.ReceivesNotifyEvents/7 test from
xorg-integration-tests:

==24736==ERROR: AddressSanitizer: heap-use-after-free on address
0x619000065020 at pc 0x55c450e2b9cf bp 0x7fffc532fd20 sp 0x7fffc532fd10
READ of size 4 at 0x619000065020 thread T0
    #0 0x55c450e2b9ce in GetMaster ../../../dix/devices.c:2722
    #1 0x55c450e9d035 in IsFloating ../../../dix/events.c:346
    #2 0x55c4513209c6 in GetDeviceUse ../../../Xi/xiquerydevice.c:525
../../../Xi/xichangehierarchy.c:95
    #4 0x55c450e3455c in RemoveDevice ../../../dix/devices.c:1204
../../../hw/xfree86/common/xf86Xinput.c:1142
    #6 0x55c450e17b04 in CloseDeviceList ../../../dix/devices.c:1038
    #7 0x55c450e1de85 in CloseDownDevices ../../../dix/devices.c:1068
    #8 0x55c450e837ef in dix_main ../../../dix/main.c:302
    #9 0x55c4517a8d93 in main ../../../dix/stubmain.c:34
(/lib/x86_64-linux-gnu/libc.so.6+0x28564)
    #11 0x55c450d0113d in _start (/usr/lib/xorg/Xorg+0x117713d)

0x619000065020 is located 160 bytes inside of 912-byte region
[0x619000064f80,0x619000065310)
freed by thread T0 here:
(/usr/lib/x86_64-linux-gnu/libasan.so.5+0x10d7cf)
    #1 0x55c450e19f1c in CloseDevice ../../../dix/devices.c:1014
    #2 0x55c450e343a4 in RemoveDevice ../../../dix/devices.c:1186
../../../hw/xfree86/common/xf86Xinput.c:1142
    #4 0x55c450e17b04 in CloseDeviceList ../../../dix/devices.c:1038
    #5 0x55c450e1de85 in CloseDownDevices ../../../dix/devices.c:1068
    #6 0x55c450e837ef in dix_main ../../../dix/main.c:302
    #7 0x55c4517a8d93 in main ../../../dix/stubmain.c:34
(/lib/x86_64-linux-gnu/libc.so.6+0x28564)

previously allocated by thread T0 here:
(/usr/lib/x86_64-linux-gnu/libasan.so.5+0x10ddc6)
    #1 0x55c450e1c57b in AddInputDevice ../../../dix/devices.c:259
    #2 0x55c450e34840 in AllocDevicePair ../../../dix/devices.c:2755
    #3 0x55c45130318f in add_master ../../../Xi/xichangehierarchy.c:152
../../../Xi/xichangehierarchy.c:465
    #5 0x55c4512cb9f5 in ProcIDispatch ../../../Xi/extinit.c:390
    #6 0x55c450e6a92b in Dispatch ../../../dix/dispatch.c:551
    #7 0x55c450e834b7 in dix_main ../../../dix/main.c:272
    #8 0x55c4517a8d93 in main ../../../dix/stubmain.c:34
(/lib/x86_64-linux-gnu/libc.so.6+0x28564)

The problem is caused by dev->master being not reset when disabling the
device, which then causes dangling pointer when the master device itself
is being deleted when exiting whole server.

Note that RecalculateMasterButtons() requires dev->master to be still
valid, so we can reset it only at the end of function.

Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
2022-02-09 11:36:48 +00:00
Povilas Kanapickas 6ef5c05728 dix: Correctly save replayed event into GrabInfoRec
When processing events we operate on InternalEvent pointers. They may
actually refer to a an instance of DeviceEvent, GestureEvent or any
other event that comprises the InternalEvent union. This works well in
practice because we always look into event type before doing anything,
except in the case of copying the event.

*dst_event = *src_event would copy whole InternalEvent event and would
cause out of bounds read in case the pointed to event was not
InternalEvent but e.g. DeviceEvent.

This regression has been introduced in
23a8b62d34.

Fixes https://gitlab.freedesktop.org/xorg/xserver/-/issues/1261

Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
2022-02-09 11:33:03 +00:00
tholin dc7cb45482 dix: Hold input lock for AttachDevice()
Fix the following race:

Possible data race during read of size 8 at 0xA112510 by thread #6
Locks held: 1, at address 0x366B40
   at 0x14C8B9: GetMaster (devices.c:2691)
   by 0x15CFC5: IsFloating (events.c:346)
   by 0x2B9554: miPointerGetScreen (mipointer.c:527)
   by 0x1A5136: xf86PostButtonEventM (xf86Xinput.c:1379)
   by 0x1A52BD: xf86PostButtonEvent (xf86Xinput.c:1345)
   by 0x485F45B: EvdevProcessEvent (in /usr/lib64/xorg/modules/input/evdev_drv.so)
   by 0x485FDAC: EvdevReadInput (in /usr/lib64/xorg/modules/input/evdev_drv.so)
   by 0x195427: xf86ReadInput (xf86Events.c:247)
   by 0x2CC113: InputReady (inputthread.c:180)
   by 0x2CE4EA: ospoll_wait (ospoll.c:657)
   by 0x2CC077: InputThreadDoWork (inputthread.c:369)
   by 0x484A336: mythread_wrapper (hg_intercepts.c:406)

This conflicts with a previous write of size 8 by thread #1
Locks held: none
   at 0x14D2C6: AttachDevice (devices.c:2609)
   by 0x15CF85: ReattachToOldMaster (events.c:1457)
   by 0x1647DD: DeactivateKeyboardGrab (events.c:1700)
   by 0x25D7F1: ProcXIUngrabDevice (xigrabdev.c:169)
   by 0x2552AD: ProcIDispatch (extinit.c:398)
   by 0x155291: Dispatch (dispatch.c:479)
   by 0x158CBA: dix_main (main.c:276)
   by 0x143A3D: main (stubmain.c:34)
 Address 0xa112510 is 336 bytes inside a block of size 904 alloc'd
   at 0x4846571: calloc (vg_replace_malloc.c:1328)
   by 0x14A0B3: AddInputDevice (devices.c:260)
   by 0x1A31A0: xf86ActivateDevice (xf86Xinput.c:365)
   by 0x1A4549: xf86NewInputDevice (xf86Xinput.c:948)
   by 0x1A4B44: NewInputDeviceRequest (xf86Xinput.c:1090)
   by 0x1B81FE: device_added (udev.c:282)
   by 0x1B8516: config_udev_init (udev.c:439)
   by 0x1B7091: config_init (config.c:50)
   by 0x197970: InitInput (xf86Init.c:814)
   by 0x158C6B: dix_main (main.c:250)
   by 0x143A3D: main (stubmain.c:34)
 Block was alloc'd by thread #1

The steps to trigger the race are:
1. Main thread does cleanup at mipointer.c:360 setting the slave device's
   miPointerPtr to null.
2. Input thread use MIPOINTER in mipointer.c and get the slave's
   miPointerPtr = null.
3. Main thread updates dev->master at devices.c:2609.
4. MIPOINTER would now return the master's miPointerPtr but the input
   thread already got the slave's miPointerPtr in step 2 and segfaults by
   null ptr deref.

Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1260
Signed-off-by: Thomas Lindroth <thomas.lindroth@gmail.com>
2022-02-03 16:56:53 +00:00
Matthieu Herrb 5b8817a019 Convert more funcs to use InternalEvent.
This fixes a crash when a DeviceEvent struct converted to
InteralEvent was beeing copied as InternalEvent (and thus
causing out of bounds reads) in ActivateGrabNoDelivery()
in events.c: 3876    *grabinfo->sync.event = *real_event;

Possible fix for https://gitlab.freedesktop.org/xorg/xserver/-/issues/1253

Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
2021-12-19 20:01:04 +00:00
Povilas Kanapickas c97397dc47 Remove autotools support
Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
2021-10-27 13:15:40 +03:00
Alex Richardson f9f705bf3c dix/privates.c: Avoid undefined behaviour after realloc()
Adding the offset between the realloc result and the old allocation to
update pointers into the new allocation is undefined behaviour: the
old pointers are no longer valid after realloc() according to the C
standard. While this works on almost all architectures and compilers,
it causes  problems on architectures that track pointer bounds (e.g.
CHERI or Arm's Morello): the DevPrivateKey pointers will still have the
bounds of the previous allocation and therefore any dereference will
result in a run-time trap.

I found this due to a crash (dereferencing an invalid capability) while
trying to run `XVnc` on a CHERI-RISC-V system. With this commit I can
successfully connect to the XVnc instance running inside a QEMU with a
VNC viewer on my host.

This also changes the check whether the allocation was moved to use
uintptr_t instead of a pointer since according to the C standard:
"The value of a pointer becomes indeterminate when the object it
points to (or just past) reaches the end of its lifetime." Casting to an
integer type avoids this undefined behaviour.

Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
2021-10-08 09:59:11 +00:00
Ignacio Casal Quinteiro 1fd5dec11b touchevents: set the screen pointer after checking the device is enabled
If the device is disabled the sprite is NULL so we get a seg fault
2021-09-07 16:58:10 +02:00
Simon Ser 7d34b1f2b7 xwayland: add -noTouchPointerEmulation
In some scenarios, the Wayland compositor might have more knowledge
than the X11 server and may be able to perform pointer emulation for
touch events better. Add a command-line switch to allow compositors
to turn Xwayland pointer emulation off.

Signed-off-by: Simon Ser <contact@emersion.fr>
2021-09-06 21:19:46 +00:00
Alex Richardson d83c84bd9d Mark the dixChangeWindowProperty() value argument as const
It is copied using memcpy() and not modified so we can add const. This
fixes a -Wincompatible-pointer-types-discards-qualifiers compiler warning
that was failing a -Werror XVnc build for me.

Signed-off-by: Alex Richardson <Alexander.Richardson@cl.cam.ac.uk>
2021-07-30 08:36:35 +00:00
Olivier Fourdan 6b47321bc6 dix: Add optional terminate delay
When the command line option "-terminate" is used, it could be
interesting to give it an optional grace period to let the Xserver
running for a little longer in case a new connection occurs.

This adds an optional parameter to the "-terminate" command line option
for this purpose.

v2: Use a delay in seconds instead of milliseconds
    (Martin Peres <martin.peres@mupuf.org>)
v3: Clarify man page entry, ensure terminateDelay is always >= 0,
    simplify TimerFree(). (Peter Hutterer <peter.hutterer@who-t.net>)

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
2021-06-07 17:28:05 +02:00
Olivier Fourdan e167299f60 xfixes: Add ClientDisconnectMode
With Wayland compositors now being able to start Xwayland on demand, the
next logical step is to be able to stop Xwayland when there is no more
need for it.

The Xserver itself is capable of terminating itself once all X11 clients
are gone, yet in a typical full session, there are a number of X11
clients running continuously (e.g. the Xsettings daemon, IBus, etc.).

Those always-running clients will prevent the Xserver from terminating,
because the actual number of X11 clients will never drop to 0. Worse,
the X11 window manager of a Wayland compositor also counts as an X11
client, hence also preventing Xwayland from stopping.

Some compositors such as mutter use the XRes extension to query the X11
clients connected, match their PID with the actual executable name and
compare those with a list of executables that can be ignored when
deciding to kill the Xserver.

But that's not just clumsy, it is also racy, because a new X11 client
might initiate a connection the X11 server right when the compositor is
about to kill it.

To solve this issue directly at the Xserver level, this add new entries
to the XFixes extension to let the X11 clients themselves specify the
disconnect mode they expect.

Typically, those X11 daemon clients would specify the disconnect mode
XFixesClientDisconnectFlagTerminate to let the Xserver know that they
should not be accounted for when checking the remaining clients prior
to terminate.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
2021-06-07 17:28:05 +02:00