Using calloc() instead of malloc() as preventive measure, so there
never can be any hidden bugs or leaks due uninitialized memory.
The extra cost of using this compiler intrinsic should be practically
impossible to measure - in many cases a good compiler can even deduce
if certain areas really don't need to be zero'd (because they're written
to right after allocation) and create more efficient machine code.
The code pathes in question are pretty cold anyways, so it's probably
not worth even thinking about potential extra runtime costs.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Even though the cases might be hypothetical, it's still better having some
tiny extra checks (that might be even optimized-out) and reduce the analyzer
noise a bit.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
In the rare case that NULL kbd is passed and also no components provided,
the corresponding error message code crashes on NULL pointer dereference.
| ../xkb/ddxLoad.c: In function ‘XkbDDXLoadKeymapByNames’:
| ../xkb/ddxLoad.c:393:25: warning: dereference of NULL ‘keybd’ [CWE-476] [-Wanalyzer-null-dereference]
| 393 | keybd->name ? keybd->name : "(unnamed keyboard)");
| | ~~~~~^~~~~~
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
The freeRules parameter is always set to TRUE, meaning always free the
XkbRF_RulesRec struct. Therefore also no need to clear out fields that
aren't going to be reused again, ever.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1840>
Allow the compiler to figure out the most efficient way to do the
struct initialization, and a little improvement on code readability.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1840>
The function is nothing more than a calloc() call, so we can spare
an actual function call here by making it static inline.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1840>
Handles common case of allocating & copying string to temporary buffer
(cherry picked from xorg/lib/libxkbfile@8a91517ca6ea77633476595b0eb5b213357c60e5)
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1821>
Fixes formatting of negative numbers, so they don't show minus sign
after the decimal point.
(cherry picked from xorg/lib/libxkbfile@d2ec504fec2550f4fd046e801b34317ef4a4bab9)
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1821>
Passing a negative value in `needed` to the `XkbResizeKeyActions()`
function can create a `newActs` array of an unespected size.
Check the value and return if it is invalid.
This error has been found by a static analysis tool. This is the report:
Error: OVERRUN (CWE-119):
libX11-1.8.7/src/xkb/XKBMAlloc.c:811: cond_const:
Checking "xkb->server->size_acts == 0" implies that
"xkb->server->size_acts" is 0 on the true branch.
libX11-1.8.7/src/xkb/XKBMAlloc.c:811: buffer_alloc:
"calloc" allocates 8 bytes dictated by parameters
"(size_t)((xkb->server->size_acts == 0) ? 1 : xkb->server->size_acts)"
and "8UL".
libX11-1.8.7/src/xkb/XKBMAlloc.c:811: var_assign:
Assigning: "newActs" = "calloc((size_t)((xkb->server->size_acts == 0) ? 1 : xkb->server->size_acts), 8UL)".
libX11-1.8.7/src/xkb/XKBMAlloc.c:815: assignment:
Assigning: "nActs" = "1".
libX11-1.8.7/src/xkb/XKBMAlloc.c:829: cond_at_least:
Checking "nCopy > 0" implies that "nCopy" is at least 1 on the
true branch.
libX11-1.8.7/src/xkb/XKBMAlloc.c:830: overrun-buffer-arg:
Overrunning buffer pointed to by "&newActs[nActs]" of 8 bytes by
passing it to a function which accesses it at byte offset 15
using argument "nCopy * 8UL" (which evaluates to 8).
# 828|
# 829| if (nCopy > 0)
# 830|-> memcpy(&newActs[nActs], XkbKeyActionsPtr(xkb, i),
# 831| nCopy * sizeof(XkbAction));
# 832| if (nCopy < nKeyActs)
(cherry picked from xorg/lib/libx11@af1312d2873d2ce49b18708a5029895aed477392)
Signed-off-by: José Expósito <jexposit@redhat.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1821>
If there was a previous radio_groups array which we failed to realloc
and freed instead, clear the array size in the XkbNamesRec.
Taken from xorg/lib/libx11@258a8ced681dc1bc50396be7439fce23f9807e2a
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1821>
If XkbChangeTypesOfKey() is called with nGroups == 0, it will resize the
key syms to 0 but leave the key actions unchanged.
If later, the same function is called with a non-zero value for nGroups,
this will cause a buffer overflow because the key actions are of the wrong
size.
To avoid the issue, make sure to resize both the key syms and key actions
when nGroups is 0.
CVE-2025-26597, ZDI-CAN-25683
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
The computation of the length in XkbSizeKeySyms() differs from what is
actually written in XkbWriteKeySyms(), leading to a heap overflow.
Fix the calculation in XkbSizeKeySyms() to match what kbWriteKeySyms()
does.
CVE-2025-26596, ZDI-CAN-25543
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
The code in XkbVModMaskText() allocates a fixed sized buffer on the
stack and copies the virtual mod name.
There's actually two issues in the code that can lead to a buffer
overflow.
First, the bound check mixes pointers and integers using misplaced
parenthesis, defeating the bound check.
But even though, if the check fails, the data is still copied, so the
stack overflow will occur regardless.
Change the logic to skip the copy entirely if the bound check fails.
CVE-2025-26595, ZDI-CAN-25545
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1828>
This (public) file isn't used by anybody outside Xserver tree
and doesn't contain anything useful anymore, so lets drop it.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1729>
These are only used inside xkb/*, so no need to keep them exported.
Also replacing some macros by inline functions in order to improve
type-safety and debugging, and adding documentation.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1729>
This function has only one caller in xkb.c, so no need to keep it exported,
can be moved over into xkb.c and made static.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1729>
The request struct's length fields aren't used anymore - we have the
client->req_len field instead, which also is bigreq-compatible.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1639>
The authorative source of the request frame size is client->req_len,
especially with big requests larger than 2^18 bytes.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1639>
Consider the following keymap:
```xkb
xkb_keymap {
xkb_keycodes {
<compose> = 135;
};
xkb_symbols {
key <compose> {
[ SetGroup(group = +1) ]
};
};
};
```
When the user presses the compose key, the following happens:
1. The compositor forwards the key to Xwayland.
2. Xwayland executes the SetGroup action and sets the base_group to 1
and the effective group to 1.
3. The compositor updates its own state and sends the effective group,
1, to Xwayland.
4. Xwayland sets the locked group to 1 and the effective group to
1 + 1 = 2.
This is wrong since pressing compose should set the effective group to 1
but to X applications the effective group appears to be 2.
This commit makes it so that Xwayland completely ignores the key
behaviors and actions of the keymap and only updates the modifier and
group components in response to the wayland modifiers events.
Signed-off-by: Julian Orth <ju.orth@gmail.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1758>
Generating the modifier modmap, the helper function generate_modkeymap()
would check the entire range up to the MAP_LENGTH.
However, the given keymap might have less keycodes than MAP_LENGTH, in
which case we would go beyond the size of the modmap, as reported by
ASAN:
==ERROR: AddressSanitizer: heap-buffer-overflow
READ of size 1 at 0x5110001c225b thread T0
#0 0x5e7369393873 in generate_modkeymap ../dix/inpututils.c:309
#1 0x5e736930dcce in ProcGetModifierMapping ../dix/devices.c:1794
#2 0x5e7369336489 in Dispatch ../dix/dispatch.c:550
#3 0x5e736934407d in dix_main ../dix/main.c:275
#5 0x7e46d47b2ecb in __libc_start_main
#6 0x5e73691be324 in _start (xserver/build/hw/xwayland/Xwayland)
Address is located 0 bytes after 219-byte region
allocated by thread T0 here:
#0 0x7e46d4cfc542 in realloc
#1 0x5e73695aa90e in _XkbCopyClientMap ../xkb/xkbUtils.c:1142
#2 0x5e73695aa90e in XkbCopyKeymap ../xkb/xkbUtils.c:1966
#3 0x5e73695b1b2f in XkbDeviceApplyKeymap ../xkb/xkbUtils.c:2023
#4 0x5e73691c6c18 in keyboard_handle_keymap ../hw/xwayland/xwayland-input.c:1194
As MAP_LENGTH is used in various code paths where the max keycode might
not be easily available, best is to always use MAP_LENGTH to allocate the
keymaps so that the code never run past the buffer size.
If the max key code is smaller than the MAP_LENGTH limit, fill-in the gap
with zeros.
That also simplifies the code slightly as we do not constantly need to
reallocate the keymap to adjust to the max key code size.
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1780
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1762>
Found by clang 13.0.1:
../xkb/xkbtext_priv.h:5:9: warning: '_XSERVER_XKB_XKBTEXT_PRIV_H' is used
as a header guard here, followed by #define of a different macro
[-Wheader-guard]
#ifndef _XSERVER_XKB_XKBTEXT_PRIV_H
^~~~~~~~~~~~~~~~~~~~~~~~~~~
../xkb/xkbtext_priv.h:6:9: note: '_XSERVER_XKB_XKBTEXt_PRIV_H' is defined
here; did you mean '_XSERVER_XKB_XKBTEXT_PRIV_H'?
#define _XSERVER_XKB_XKBTEXt_PRIV_H
^~~~~~~~~~~~~~~~~~~~~~~~~~~
_XSERVER_XKB_XKBTEXT_PRIV_H
Fixes: 434044cb0 ("xkb: unexport functions from xkbtext.c")
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1740>
The _XkbSetCompatMap() function attempts to resize the `sym_interpret`
buffer.
However, It didn't update its size properly. It updated `num_si` only,
without updating `size_si`.
This may lead to local privilege escalation if the server is run as root
or remote code execution (e.g. x11 over ssh).
CVE-2024-9632, ZDI-CAN-24756
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Tested-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: José Expósito <jexposit@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1733>
fix warning on unused variable:
> ../xkb/xkb.c:3576:18: warning: variable 'extDevReason' set but not used [-Wunused-but-set-variable]
> unsigned int extDevReason;
^
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1426>
Enrico Weigelt, metux IT consult
Alan Coopersmith
Martin Burggraf
José Expósito
Olivier Fourdan
Julian Orth
Matthieu Herrb