xorg-x11-server/SOURCES/0001-Xi-randr-fix-handling-of-PropModeAppend-Prepend.patch

81 lines
2.9 KiB
Diff

From a31ba141824a7649e11f0ef7673718ce559d6337 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Tue, 3 Oct 2023 11:53:05 +1000
Subject: [PATCH xserver 1/4] 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>
---
Xi/xiproperty.c | 4 ++--
randr/rrproperty.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/Xi/xiproperty.c b/Xi/xiproperty.c
index 6ec419e870..563c4f31a5 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 c2fb9585c6..25469f57b2 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)
--
2.41.0