You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
78 lines
3.2 KiB
78 lines
3.2 KiB
11 months ago
|
From 1801fe0ac3926882d47d7e1ad6c0518a2cdffd41 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Povilas Kanapickas <povilas@radix.lt>
|
||
|
|
Date: Sun, 19 Dec 2021 18:11:07 +0200
|
||
|
|
Subject: [PATCH] dix: Fix use after free in input device shutdown
|
||
|
|
|
||
|
|
This fixes access to freed heap memory via dev->master. E.g. when
|
||
|
|
running BarrierNotify.ReceivesNotifyEvents/7 test from
|
||
|
|
xorg-integration-tests:
|
||
|
|
|
||
|
|
==24736==ERROR: AddressSanitizer: heap-use-after-free on address
|
||
|
|
0x619000065020 at pc 0x55c450e2b9cf bp 0x7fffc532fd20 sp 0x7fffc532fd10
|
||
|
|
READ of size 4 at 0x619000065020 thread T0
|
||
|
|
#0 0x55c450e2b9ce in GetMaster ../../../dix/devices.c:2722
|
||
|
|
#1 0x55c450e9d035 in IsFloating ../../../dix/events.c:346
|
||
|
|
#2 0x55c4513209c6 in GetDeviceUse ../../../Xi/xiquerydevice.c:525
|
||
|
|
../../../Xi/xichangehierarchy.c:95
|
||
|
|
#4 0x55c450e3455c in RemoveDevice ../../../dix/devices.c:1204
|
||
|
|
../../../hw/xfree86/common/xf86Xinput.c:1142
|
||
|
|
#6 0x55c450e17b04 in CloseDeviceList ../../../dix/devices.c:1038
|
||
|
|
#7 0x55c450e1de85 in CloseDownDevices ../../../dix/devices.c:1068
|
||
|
|
#8 0x55c450e837ef in dix_main ../../../dix/main.c:302
|
||
|
|
#9 0x55c4517a8d93 in main ../../../dix/stubmain.c:34
|
||
|
|
(/lib/x86_64-linux-gnu/libc.so.6+0x28564)
|
||
|
|
#11 0x55c450d0113d in _start (/usr/lib/xorg/Xorg+0x117713d)
|
||
|
|
|
||
|
|
0x619000065020 is located 160 bytes inside of 912-byte region
|
||
|
|
[0x619000064f80,0x619000065310)
|
||
|
|
freed by thread T0 here:
|
||
|
|
(/usr/lib/x86_64-linux-gnu/libasan.so.5+0x10d7cf)
|
||
|
|
#1 0x55c450e19f1c in CloseDevice ../../../dix/devices.c:1014
|
||
|
|
#2 0x55c450e343a4 in RemoveDevice ../../../dix/devices.c:1186
|
||
|
|
../../../hw/xfree86/common/xf86Xinput.c:1142
|
||
|
|
#4 0x55c450e17b04 in CloseDeviceList ../../../dix/devices.c:1038
|
||
|
|
#5 0x55c450e1de85 in CloseDownDevices ../../../dix/devices.c:1068
|
||
|
|
#6 0x55c450e837ef in dix_main ../../../dix/main.c:302
|
||
|
|
#7 0x55c4517a8d93 in main ../../../dix/stubmain.c:34
|
||
|
|
(/lib/x86_64-linux-gnu/libc.so.6+0x28564)
|
||
|
|
|
||
|
|
previously allocated by thread T0 here:
|
||
|
|
(/usr/lib/x86_64-linux-gnu/libasan.so.5+0x10ddc6)
|
||
|
|
#1 0x55c450e1c57b in AddInputDevice ../../../dix/devices.c:259
|
||
|
|
#2 0x55c450e34840 in AllocDevicePair ../../../dix/devices.c:2755
|
||
|
|
#3 0x55c45130318f in add_master ../../../Xi/xichangehierarchy.c:152
|
||
|
|
../../../Xi/xichangehierarchy.c:465
|
||
|
|
#5 0x55c4512cb9f5 in ProcIDispatch ../../../Xi/extinit.c:390
|
||
|
|
#6 0x55c450e6a92b in Dispatch ../../../dix/dispatch.c:551
|
||
|
|
#7 0x55c450e834b7 in dix_main ../../../dix/main.c:272
|
||
|
|
#8 0x55c4517a8d93 in main ../../../dix/stubmain.c:34
|
||
|
|
(/lib/x86_64-linux-gnu/libc.so.6+0x28564)
|
||
|
|
|
||
|
|
The problem is caused by dev->master being not reset when disabling the
|
||
|
|
device, which then causes dangling pointer when the master device itself
|
||
|
|
is being deleted when exiting whole server.
|
||
|
|
|
||
|
|
Note that RecalculateMasterButtons() requires dev->master to be still
|
||
|
|
valid, so we can reset it only at the end of function.
|
||
|
|
|
||
|
|
Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
|
||
|
|
---
|
||
|
|
dix/devices.c | 1 +
|
||
|
|
1 file changed, 1 insertion(+)
|
||
|
|
|
||
|
|
diff --git a/dix/devices.c b/dix/devices.c
|
||
|
|
index e62c34c55..5f9ce1678 100644
|
||
|
|
--- a/dix/devices.c
|
||
|
|
+++ b/dix/devices.c
|
||
|
|
@@ -520,6 +520,7 @@ DisableDevice(DeviceIntPtr dev, BOOL sendevent)
|
||
|
|
}
|
||
|
|
|
||
|
|
RecalculateMasterButtons(dev);
|
||
|
|
+ dev->master = NULL;
|
||
|
|
|
||
|
|
return TRUE;
|
||
|
|
}
|
||
|
|
--
|
||
|
|
2.43.0
|
||
|
|
|