If we fail to set up the default rules our keymap is likely going to end
up messed up, which means the client/user can't work correctly anyway.
And if we're that low on memory that we can't allocate these rules,
we're about to fall over anyway so why bother.
Co-Authored-by: Claude Code <noreply@anthropic.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2184>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
CHK_MASK_LEGAL expands to 'return BadValue' when the check fails and
doesn't clean up the already allocated names.keycodes, names.types, etc.
Move the check up so we don't need any cleanup code.
Co-Authored-by: Claude Code <noreply@anthropic.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2184>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Finally, after 33 years something deals with the allocation failure. Put
on a party hat!
Co-Authored-by: Claude Code <noreply@anthropic.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2184>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Structs that are sent to the client may leak data via unititialized
padding bytes. Let's not do that.
Co-Authored-by: Claude Code <noreply@anthropic.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2185>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
As reported by valgrind:
== Conditional jump or move depends on uninitialised value(s)
== at 0x5CBE66: SrvXkbAddGeomKeyAlias (XKBGAlloc.c:585)
== by 0x5AC7D5: _CheckSetGeom (xkb.c:5607)
== by 0x5AC952: _XkbSetGeometry (xkb.c:5643)
== by 0x5ACB58: ProcXkbSetGeometry (xkb.c:5684)
== by 0x5B0DAC: ProcXkbDispatch (xkb.c:7070)
== by 0x4A28C5: Dispatch (dispatch.c:553)
== by 0x4B0B24: dix_main (main.c:274)
== by 0x42915E: main (stubmain.c:34)
== Uninitialised value was created by a heap allocation
== at 0x4840B26: malloc (vg_replace_malloc.c:447)
== by 0x5E13B0: AllocateInputBuffer (io.c:981)
== by 0x5E05CD: InsertFakeRequest (io.c:516)
== by 0x4AA860: NextAvailableClient (dispatch.c:3629)
== by 0x5DE0D7: AllocNewConnection (connection.c:628)
== by 0x5DE2C6: EstablishNewConnections (connection.c:692)
== by 0x5DE600: HandleNotifyFd (connection.c:809)
== by 0x5E2598: ospoll_wait (ospoll.c:660)
== by 0x5DA00C: WaitForSomething (WaitFor.c:208)
== by 0x4A26E5: Dispatch (dispatch.c:493)
== by 0x4B0B24: dix_main (main.c:274)
== by 0x42915E: main (stubmain.c:34)
Each key alias entry contains two key names (the alias and the real key
name), each of size XkbKeyNameLength.
The current bounds check only validates the first name, allowing
XkbAddGeomKeyAlias to potentially read uninitialized memory when
accessing the second name at &wire[XkbKeyNameLength].
To fix this, change the value to check to use 2 * XkbKeyNameLength to
validate the bounds.
CVE-2026-34000, ZDI-CAN-28679
This vulnerability was discovered by:
Jan-Niklas Sohn working with TrendAI Zero Day Initiative
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
If the "compat" buffer has previously been truncated, there will be
unused space in the buffer. The code uses this space, but does not
update the number of valid entries in the buffer.
In the best case, this leads to the new compat entries being ignored. In the
worst case, if there are any "skipped" compat entries, the number of
valid entries will be corrupted, potentially leading to a buffer read
overrun when processing a future request.
Set the number of used "compat" entries when re-using previously
allocated space in the buffer.
CVE-2026-33999, ZDI-CAN-28593
This vulnerability was discovered by:
Jan-Niklas Sohn working with TrendAI Zero Day Initiative
Signed-off-by: Peter Harris <pharris2@rocketsoftware.com>
Acked-by: Olivier Fourdan <ofourdan@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
A key type that has no level names is legit. Before this commit,
`XkbCopyKeymap` would make such level inconsistent by setting its
number of levels to 0 while keeping its map entries. It suffices
to clear the names array.
Fixed by copying the level count from the source type.
WARNING: this will trigger an error in `XkbGetNames`, which worked
before this commit only by chance. This is fixed in the next commit.
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2082>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Before this commit the count of key type level names was wrongly set
in `XkbGetNames`: for key type without names, it was set to the level
count, while it should be 0:
- `XkbComputeGetNamesReplySize()` does not account key type without
level names;
- `XkbSendNames()` does not write any level entry for key types without
level names.
This causes a mismatch offset while parsing the response and its
processing would ultimately fail.
Fixed by setting the correct level name count: 0 if there is no level
name, else the number of levels.
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2082>
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
len calculation and strncpy limit were off by one when prefixing
"vmod_" to the virtual modifier name. This could write the final
NULL one byte past the allocated buffer from tbGetBuffer().
Use proper allocation len for prefix to avoid writing out-of-bounds.
Found by Linux Verification Center (linuxtesting.org) with SVACE
Signed-off-by: Mikhail Dmitrichenko <m.dmitrichenko222@gmail.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2175>
In XkbAddGeomDoodad(), when adding a doodad to a specific section
(section != NULL), there is a comparison between section->num_doodads
and geom->sz_doodads instead of the section's own section->sz_doodads.
The else branch (global geometry doodads) was already correct.
Compare section->num_doodads against section->sz_doodads to prevent
a potential out-of-bounds.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Mikhail Dmitrichenko <m.dmitrichenko222@gmail.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2174>
Similar to the recent fixes, add more _XkbCheckRequestBounds() to the
functions that loop over the request data, i.e.:
* CheckKeySyms()
* CheckKeyActions()
* CheckKeyBehaviors()
* CheckVirtualMods()
* CheckKeyExplicit()
* CheckVirtualModMap()
* _XkbSetMapChecks()
All these are static functions so we can add the client to the parameters
without breaking any API.
See also:
CVE-2026-34003, ZDI-CAN-28736, CVE-2026-34002, ZDI-CAN-28737
v2: Check for "nSyms != 0" in CheckKeySyms() to avoid false positives.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
As reported by valgrind:
== Conditional jump or move depends on uninitialised value(s)
== at 0x547E5B: CheckModifierMap (xkb.c:1972)
== by 0x54A086: _XkbSetMapChecks (xkb.c:2574)
== by 0x54A845: ProcXkbSetMap (xkb.c:2741)
== by 0x556EF4: ProcXkbDispatch (xkb.c:7048)
== by 0x454A8C: Dispatch (dispatch.c:553)
== by 0x462CEB: dix_main (main.c:274)
== by 0x405EA7: main (stubmain.c:34)
== Uninitialised value was created by a heap allocation
== at 0x4840B26: malloc (vg_replace_malloc.c:447)
== by 0x592D5A: AllocateInputBuffer (io.c:981)
== by 0x591F77: InsertFakeRequest (io.c:516)
== by 0x45CA27: NextAvailableClient (dispatch.c:3629)
== by 0x58FA81: AllocNewConnection (connection.c:628)
== by 0x58FC70: EstablishNewConnections (connection.c:692)
== by 0x58FFAA: HandleNotifyFd (connection.c:809)
== by 0x593F42: ospoll_wait (ospoll.c:660)
== by 0x58B9B6: WaitForSomething (WaitFor.c:208)
== by 0x4548AC: Dispatch (dispatch.c:493)
== by 0x462CEB: dix_main (main.c:274)
== by 0x405EA7: main (stubmain.c:34)
The issue is that the loop in CheckModifierMap() reads from wire without
verifying that the data is within the request bounds.
The req->totalModMapKeys value could exceed the actual data provided,
causing reads of uninitialized memory.
To fix that issue, we add a bounds check using _XkbCheckRequestBounds,
but for that, we need to also pass a ClientPtr parameter, which is not
a problem since CheckModifierMap() is a private, static function.
CVE-2026-34002, ZDI-CAN-28737
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
The function CheckKeyTypes() will loop over the client's request but
won't perform any additional bound checking to ensure that the data
read remains within the request bounds.
As a result, a specifically crafted request may cause CheckKeyTypes() to
read past the request data, as reported by valgrind:
== Invalid read of size 2
== at 0x5A3D1D: CheckKeyTypes (xkb.c:1694)
== by 0x5A6A9C: _XkbSetMapChecks (xkb.c:2515)
== by 0x5A759E: ProcXkbSetMap (xkb.c:2736)
== by 0x5BF832: SProcXkbSetMap (xkbSwap.c:245)
== by 0x5C05ED: SProcXkbDispatch (xkbSwap.c:501)
== by 0x4A20DF: Dispatch (dispatch.c:551)
== by 0x4B03B4: dix_main (main.c:277)
== by 0x428941: main (stubmain.c:34)
== Address is 30 bytes after a block of size 28,672 in arena "client"
==
== Invalid read of size 2
== at 0x5A3AB6: CheckKeyTypes (xkb.c:1669)
== by 0x5A6A9C: _XkbSetMapChecks (xkb.c:2515)
== by 0x5A759E: ProcXkbSetMap (xkb.c:2736)
== by 0x5BF832: SProcXkbSetMap (xkbSwap.c:245)
== by 0x5C05ED: SProcXkbDispatch (xkbSwap.c:501)
== by 0x4A20DF: Dispatch (dispatch.c:551)
== by 0x4B03B4: dix_main (main.c:277)
== by 0x428941: main (stubmain.c:34)
== Address is 2 bytes after a block of size 28,672 alloc'd
== at 0x4848897: realloc (vg_replace_malloc.c:1804)
== by 0x5E357A: ReadRequestFromClient (io.c:336)
== by 0x4A1FAB: Dispatch (dispatch.c:519)
== by 0x4B03B4: dix_main (main.c:277)
== by 0x428941: main (stubmain.c:34)
==
== Invalid write of size 2
== at 0x5A3AD7: CheckKeyTypes (xkb.c:1669)
== by 0x5A6A9C: _XkbSetMapChecks (xkb.c:2515)
== by 0x5A759E: ProcXkbSetMap (xkb.c:2736)
== by 0x5BF832: SProcXkbSetMap (xkbSwap.c:245)
== by 0x5C05ED: SProcXkbDispatch (xkbSwap.c:501)
== by 0x4A20DF: Dispatch (dispatch.c:551)
== by 0x4B03B4: dix_main (main.c:277)
== by 0x428941: main (stubmain.c:34)
== Address is 2 bytes after a block of size 28,672 alloc'd
== at 0x4848897: realloc (vg_replace_malloc.c:1804)
== by 0x5E357A: ReadRequestFromClient (io.c:336)
== by 0x4A1FAB: Dispatch (dispatch.c:519)
== by 0x4B03B4: dix_main (main.c:277)
== by 0x428941: main (stubmain.c:34)
==
To avoid that issue, add additional bounds checking within the loops by
calling _XkbCheckRequestBounds() and report an error if we are to read
past the client's request.
CVE-2026-34003, ZDI-CAN-28736
This vulnerability was discovered by:
Jan-Niklas Sohn working with TrendAI Zero Day Initiative
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2176>
Reported in #1817:
xwayland-24.1.6/redhat-linux-build/../xkb/xkbInit.c:527:5:
warning[-Wanalyzer-malloc-leak]: leak of ‘rmlvo_dflts.layout’
xwayland-24.1.6/redhat-linux-build/../xkb/xkbInit.c:527:5:
warning[-Wanalyzer-malloc-leak]: leak of ‘rmlvo_dflts.model’
xwayland-24.1.6/redhat-linux-build/../xkb/xkbInit.c:527:5:
warning[-Wanalyzer-malloc-leak]: leak of ‘rmlvo_dflts.options’
xwayland-24.1.6/redhat-linux-build/../xkb/xkbInit.c:527:5:
warning[-Wanalyzer-malloc-leak]: leak of ‘rmlvo_dflts.rules’
xwayland-24.1.6/redhat-linux-build/../xkb/xkbInit.c:527:5:
warning[-Wanalyzer-malloc-leak]: leak of ‘rmlvo_dflts.variant’
Fixes: 56a5955c8 ("xkb: strdup the values returned by XkbGetRulesDflts")
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2169>
Brought back the code removed in that commit so that we can bring back
Cygwin support.
Small changes are done in the process of resolving conflicts against the
current head.
Some checks have not been reverted, because they were not necessary
anymore.
Signed-off-by: b-aaz <b-aazbsd@proton.me>
dixAddAtom() is safe to call multiple times with same name,
always return the corresponding XID, no matter whether the
atom just been newly created or already existed.
Thus, there's no need for special server generation treatment here.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
The final one, SProcXkbSelectEvents(), is a bit more complex. Just moving
this into ProcXkbSelectEvents() for now, so we can drop also the swapped
dispatcher. There's still a lot of room for simplications, but leaving
this for follow-up work.
Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
The XkbCompatMap structure stores its "num_si" and "size_si" fields
using an unsigned short.
However, the function _XkbSetCompatMap() will store the sum of the
input data "firstSI" and "nSI" in both XkbCompatMap's "num_si" and
"size_si" without first checking if the sum overflows the maximum
unsigned short value, leading to a possible overflow.
To avoid the issue, check whether the sum does not exceed the maximum
unsigned short value, or return a "BadValue" error otherwise.
CVE-2025-62231, ZDI-CAN-27560
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: Michel Dänzer <mdaenzer@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2086>
XkbRemoveResourceClient() would free the XkbInterest data associated
with the device, but not the resource associated with it.
As a result, when the client terminates, the resource delete function
gets called and accesses already freed memory:
| Invalid read of size 8
| at 0x5BC0C0: XkbRemoveResourceClient (xkbEvents.c:1047)
| by 0x5B3391: XkbClientGone (xkb.c:7094)
| by 0x4DF138: doFreeResource (resource.c:890)
| by 0x4DFB50: FreeClientResources (resource.c:1156)
| by 0x4A9A59: CloseDownClient (dispatch.c:3550)
| by 0x5E0A53: ClientReady (connection.c:601)
| by 0x5E4FEF: ospoll_wait (ospoll.c:657)
| by 0x5DC834: WaitForSomething (WaitFor.c:206)
| by 0x4A1BA5: Dispatch (dispatch.c:491)
| by 0x4B0070: dix_main (main.c:277)
| by 0x4285E7: main (stubmain.c:34)
| Address 0x1893e278 is 184 bytes inside a block of size 928 free'd
| at 0x4842E43: free (vg_replace_malloc.c:989)
| by 0x49C1A6: CloseDevice (devices.c:1067)
| by 0x49C522: CloseOneDevice (devices.c:1193)
| by 0x49C6E4: RemoveDevice (devices.c:1244)
| by 0x5873D4: remove_master (xichangehierarchy.c:348)
| by 0x587921: ProcXIChangeHierarchy (xichangehierarchy.c:504)
| by 0x579BF1: ProcIDispatch (extinit.c:390)
| by 0x4A1D85: Dispatch (dispatch.c:551)
| by 0x4B0070: dix_main (main.c:277)
| by 0x4285E7: main (stubmain.c:34)
| Block was alloc'd at
| at 0x48473F3: calloc (vg_replace_malloc.c:1675)
| by 0x49A118: AddInputDevice (devices.c:262)
| by 0x4A0E58: AllocDevicePair (devices.c:2846)
| by 0x5866EE: add_master (xichangehierarchy.c:153)
| by 0x5878C2: ProcXIChangeHierarchy (xichangehierarchy.c:493)
| by 0x579BF1: ProcIDispatch (extinit.c:390)
| by 0x4A1D85: Dispatch (dispatch.c:551)
| by 0x4B0070: dix_main (main.c:277)
| by 0x4285E7: main (stubmain.c:34)
To avoid that issue, make sure to free the resources when freeing the
device XkbInterest data.
CVE-2025-62230, ZDI-CAN-27545
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: Michel Dänzer <mdaenzer@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2086>
Currently, the resource in only available to the xkb.c source file.
In preparation for the next commit, to be able to free the resources
from XkbRemoveResourceClient(), make that variable private instead.
This is related to:
CVE-2025-62230, ZDI-CAN-27545
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: Michel Dänzer <mdaenzer@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2086>
