82 lines
3.0 KiB
Diff
82 lines
3.0 KiB
Diff
From 1e8478455458e998dd366d2cd23d2aeab2bdeee5 Mon Sep 17 00:00:00 2001
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From: Peter Hutterer <peter.hutterer@who-t.net>
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Date: Tue, 3 Oct 2023 11:53:05 +1000
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Subject: [PATCH xserver] Xi/randr: fix handling of PropModeAppend/Prepend
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The handling of appending/prepending properties was incorrect, with at
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least two bugs: the property length was set to the length of the new
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part only, i.e. appending or prepending N elements to a property with P
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existing elements always resulted in the property having N elements
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instead of N + P.
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Second, when pre-pending a value to a property, the offset for the old
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values was incorrect, leaving the new property with potentially
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uninitalized values and/or resulting in OOB memory writes.
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For example, prepending a 3 element value to a 5 element property would
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result in this 8 value array:
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[N, N, N, ?, ?, P, P, P ] P, P
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^OOB write
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The XI2 code is a copy/paste of the RandR code, so the bug exists in
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both.
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CVE-2023-5367, ZDI-CAN-22153
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This vulnerability was discovered by:
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Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
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Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
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(cherry picked from commit 541ab2ecd41d4d8689e71855d93e492bc554719a)
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---
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Xi/xiproperty.c | 4 ++--
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randr/rrproperty.c | 4 ++--
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2 files changed, 4 insertions(+), 4 deletions(-)
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diff --git a/Xi/xiproperty.c b/Xi/xiproperty.c
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index 066ba21fba..d315f04d0e 100644
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--- a/Xi/xiproperty.c
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+++ b/Xi/xiproperty.c
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@@ -730,7 +730,7 @@ XIChangeDeviceProperty(DeviceIntPtr dev, Atom property, Atom type,
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XIDestroyDeviceProperty(prop);
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return BadAlloc;
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}
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- new_value.size = len;
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+ new_value.size = total_len;
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new_value.type = type;
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new_value.format = format;
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@@ -747,7 +747,7 @@ XIChangeDeviceProperty(DeviceIntPtr dev, Atom property, Atom type,
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case PropModePrepend:
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new_data = new_value.data;
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old_data = (void *) (((char *) new_value.data) +
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- (prop_value->size * size_in_bytes));
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+ (len * size_in_bytes));
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break;
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}
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if (new_data)
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diff --git a/randr/rrproperty.c b/randr/rrproperty.c
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index c2fb9585c6..25469f57b2 100644
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--- a/randr/rrproperty.c
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+++ b/randr/rrproperty.c
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@@ -209,7 +209,7 @@ RRChangeOutputProperty(RROutputPtr output, Atom property, Atom type,
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RRDestroyOutputProperty(prop);
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return BadAlloc;
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}
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- new_value.size = len;
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+ new_value.size = total_len;
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new_value.type = type;
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new_value.format = format;
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@@ -226,7 +226,7 @@ RRChangeOutputProperty(RROutputPtr output, Atom property, Atom type,
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case PropModePrepend:
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new_data = new_value.data;
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old_data = (void *) (((char *) new_value.data) +
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- (prop_value->size * size_in_bytes));
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+ (len * size_in_bytes));
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break;
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}
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if (new_data)
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--
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2.41.0
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