From 10c94238bdad17c11707e0bdaaa3a9cd54c504be Mon Sep 17 00:00:00 2001 From: Olivier Fourdan Date: Wed, 10 Sep 2025 15:58:57 +0200 Subject: [PATCH] xkb: Free the XKB resource when freeing XkbInterest MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Michel Dänzer Part-of: --- xkb/xkbEvents.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/xkb/xkbEvents.c b/xkb/xkbEvents.c index cfe9ba11c2..132b6cbde0 100644 --- a/xkb/xkbEvents.c +++ b/xkb/xkbEvents.c @@ -1055,6 +1055,7 @@ XkbRemoveResourceClient(DevicePtr inDev, XID id) autoCtrls = interest->autoCtrls; autoValues = interest->autoCtrlValues; client = interest->client; + FreeResource(interest->resource, RT_XKBCLIENT); free(interest); found = TRUE; } @@ -1066,6 +1067,7 @@ XkbRemoveResourceClient(DevicePtr inDev, XID id) autoCtrls = victim->autoCtrls; autoValues = victim->autoCtrlValues; client = victim->client; + FreeResource(victim->resource, RT_XKBCLIENT); free(victim); found = TRUE; } -- GitLab