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xkb: Free the XKB resource when freeing XkbInterest

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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>
This commit is contained in:
Olivier Fourdan 2025-09-10 15:58:57 +02:00
parent 99790a2c92
commit 10c94238bd
1 changed files with 2 additions and 0 deletions
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2
xkb/xkbEvents.c
View file

@ -1055,6 +1055,7 @@ XkbRemoveResourceClient(DevicePtr inDev, XID id)
autoCtrls = interest->autoCtrls; autoCtrls = interest->autoCtrls;
autoValues = interest->autoCtrlValues; autoValues = interest->autoCtrlValues;
client = interest->client; client = interest->client;
FreeResource(interest->resource, RT_XKBCLIENT);
free(interest); free(interest);
found = TRUE; found = TRUE;
} }
@ -1066,6 +1067,7 @@ XkbRemoveResourceClient(DevicePtr inDev, XID id)
autoCtrls = victim->autoCtrls; autoCtrls = victim->autoCtrls;
autoValues = victim->autoCtrlValues; autoValues = victim->autoCtrlValues;
client = victim->client; client = victim->client;
FreeResource(victim->resource, RT_XKBCLIENT);
free(victim); free(victim);
found = TRUE; found = TRUE;
} }