diff options
Diffstat (limited to 'extra/source/tigervnc/patches/xorg-server/CVE-2024-21885.patch')
-rw-r--r-- | extra/source/tigervnc/patches/xorg-server/CVE-2024-21885.patch | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/extra/source/tigervnc/patches/xorg-server/CVE-2024-21885.patch b/extra/source/tigervnc/patches/xorg-server/CVE-2024-21885.patch new file mode 100644 index 000000000..949efd7c6 --- /dev/null +++ b/extra/source/tigervnc/patches/xorg-server/CVE-2024-21885.patch @@ -0,0 +1,109 @@ +From 4a5e9b1895627d40d26045bd0b7ef3dce503cbd1 Mon Sep 17 00:00:00 2001 +From: Peter Hutterer <peter.hutterer@who-t.net> +Date: Thu, 4 Jan 2024 10:01:24 +1000 +Subject: [PATCH] Xi: flush hierarchy events after adding/removing master + devices + +The `XISendDeviceHierarchyEvent()` function allocates space to store up +to `MAXDEVICES` (256) `xXIHierarchyInfo` structures in `info`. + +If a device with a given ID was removed and a new device with the same +ID added both in the same operation, the single device ID will lead to +two info structures being written to `info`. + +Since this case can occur for every device ID at once, a total of two +times `MAXDEVICES` info structures might be written to the allocation. + +To avoid it, once one add/remove master is processed, send out the +device hierarchy event for the current state and continue. That event +thus only ever has exactly one of either added/removed in it (and +optionally slave attached/detached). + +CVE-2024-21885, ZDI-CAN-22744 + +This vulnerability was discovered by: +Jan-Niklas Sohn working with Trend Micro Zero Day Initiative +--- + Xi/xichangehierarchy.c | 27 ++++++++++++++++++++++----- + 1 file changed, 22 insertions(+), 5 deletions(-) + +diff --git a/Xi/xichangehierarchy.c b/Xi/xichangehierarchy.c +index d2d985848d..72d00451e3 100644 +--- a/Xi/xichangehierarchy.c ++++ b/Xi/xichangehierarchy.c +@@ -416,6 +416,11 @@ ProcXIChangeHierarchy(ClientPtr client) + size_t len; /* length of data remaining in request */ + int rc = Success; + int flags[MAXDEVICES] = { 0 }; ++ enum { ++ NO_CHANGE, ++ FLUSH, ++ CHANGED, ++ } changes = NO_CHANGE; + + REQUEST(xXIChangeHierarchyReq); + REQUEST_AT_LEAST_SIZE(xXIChangeHierarchyReq); +@@ -465,8 +470,9 @@ ProcXIChangeHierarchy(ClientPtr client) + rc = add_master(client, c, flags); + if (rc != Success) + goto unwind; +- } ++ changes = FLUSH; + break; ++ } + case XIRemoveMaster: + { + xXIRemoveMasterInfo *r = (xXIRemoveMasterInfo *) any; +@@ -475,8 +481,9 @@ ProcXIChangeHierarchy(ClientPtr client) + rc = remove_master(client, r, flags); + if (rc != Success) + goto unwind; +- } ++ changes = FLUSH; + break; ++ } + case XIDetachSlave: + { + xXIDetachSlaveInfo *c = (xXIDetachSlaveInfo *) any; +@@ -485,8 +492,9 @@ ProcXIChangeHierarchy(ClientPtr client) + rc = detach_slave(client, c, flags); + if (rc != Success) + goto unwind; +- } ++ changes = CHANGED; + break; ++ } + case XIAttachSlave: + { + xXIAttachSlaveInfo *c = (xXIAttachSlaveInfo *) any; +@@ -495,16 +503,25 @@ ProcXIChangeHierarchy(ClientPtr client) + rc = attach_slave(client, c, flags); + if (rc != Success) + goto unwind; ++ changes = CHANGED; ++ break; + } ++ default: + break; + } + ++ if (changes == FLUSH) { ++ XISendDeviceHierarchyEvent(flags); ++ memset(flags, 0, sizeof(flags)); ++ changes = NO_CHANGE; ++ } ++ + len -= any->length * 4; + any = (xXIAnyHierarchyChangeInfo *) ((char *) any + any->length * 4); + } + + unwind: +- +- XISendDeviceHierarchyEvent(flags); ++ if (changes != NO_CHANGE) ++ XISendDeviceHierarchyEvent(flags); + return rc; + } +-- +GitLab + |