diff options
| author | Peter Hutterer <peter.hutterer@who-t.net> | 2023-10-03 11:53:05 +1000 |
|---|---|---|
| committer | Peter Hutterer <peter.hutterer@who-t.net> | 2023-10-25 11:49:11 +1000 |
| commit | 1e8478455458e998dd366d2cd23d2aeab2bdeee5 (patch) | |
| tree | 9812636259175960069d71ea0129d1272bb46496 | |
| parent | 829a99117586626e15c32ca7d62d6afdcf812b37 (diff) | |
Xi/randr: fix handling of PropModeAppend/Prepend
The handling of appending/prepending properties was incorrect, with at
least two bugs: the property length was set to the length of the new
part only, i.e. appending or prepending N elements to a property with P
existing elements always resulted in the property having N elements
instead of N + P.
Second, when pre-pending a value to a property, the offset for the old
values was incorrect, leaving the new property with potentially
uninitalized values and/or resulting in OOB memory writes.
For example, prepending a 3 element value to a 5 element property would
result in this 8 value array:
[N, N, N, ?, ?, P, P, P ] P, P
^OOB write
The XI2 code is a copy/paste of the RandR code, so the bug exists in
both.
CVE-2023-5367, ZDI-CAN-22153
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit 541ab2ecd41d4d8689e71855d93e492bc554719a)
| -rw-r--r-- | Xi/xiproperty.c | 4 | ||||
| -rw-r--r-- | randr/rrproperty.c | 4 |
2 files changed, 4 insertions, 4 deletions
diff --git a/Xi/xiproperty.c b/Xi/xiproperty.c index 066ba21fb..d315f04d0 100644 --- a/Xi/xiproperty.c +++ b/Xi/xiproperty.c @@ -730,7 +730,7 @@ XIChangeDeviceProperty(DeviceIntPtr dev, Atom property, Atom type, XIDestroyDeviceProperty(prop); return BadAlloc; } - new_value.size = len; + new_value.size = total_len; new_value.type = type; new_value.format = format; @@ -747,7 +747,7 @@ XIChangeDeviceProperty(DeviceIntPtr dev, Atom property, Atom type, case PropModePrepend: new_data = new_value.data; old_data = (void *) (((char *) new_value.data) + - (prop_value->size * size_in_bytes)); + (len * size_in_bytes)); break; } if (new_data) diff --git a/randr/rrproperty.c b/randr/rrproperty.c index c2fb9585c..25469f57b 100644 --- a/randr/rrproperty.c +++ b/randr/rrproperty.c @@ -209,7 +209,7 @@ RRChangeOutputProperty(RROutputPtr output, Atom property, Atom type, RRDestroyOutputProperty(prop); return BadAlloc; } - new_value.size = len; + new_value.size = total_len; new_value.type = type; new_value.format = format; @@ -226,7 +226,7 @@ RRChangeOutputProperty(RROutputPtr output, Atom property, Atom type, case PropModePrepend: new_data = new_value.data; old_data = (void *) (((char *) new_value.data) + - (prop_value->size * size_in_bytes)); + (len * size_in_bytes)); break; } if (new_data) |