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| | Fix CVE-2021-3472:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3472
https://seclists.org/oss-sec/2021/q2/20
Patch copied from upstream source repository:
https://gitlab.freedesktop.org/xorg/xserver/-/commit/7aaf54a1884f71dc363f0b884e57bcb67407a6cd
From 7aaf54a1884f71dc363f0b884e57bcb67407a6cd Mon Sep 17 00:00:00 2001
From: Matthieu Herrb <matthieu@herrb.eu>
Date: Sun, 21 Mar 2021 18:38:57 +0100
Subject: [PATCH] Fix XChangeFeedbackControl() request underflow
CVE-2021-3472 / ZDI-CAN-1259
This vulnerability was discovered by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Matthieu Herrb <matthieu@herrb.eu>
---
Xi/chgfctl.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/Xi/chgfctl.c b/Xi/chgfctl.c
index 1de4da9ef..7a597e43d 100644
--- a/Xi/chgfctl.c
+++ b/Xi/chgfctl.c
@@ -464,8 +464,11 @@ ProcXChangeFeedbackControl(ClientPtr client)
break;
case StringFeedbackClass:
{
- xStringFeedbackCtl *f = ((xStringFeedbackCtl *) &stuff[1]);
+ xStringFeedbackCtl *f;
+ REQUEST_AT_LEAST_EXTRA_SIZE(xChangeFeedbackControlReq,
+ sizeof(xStringFeedbackCtl));
+ f = ((xStringFeedbackCtl *) &stuff[1]);
if (client->swapped) {
if (len < bytes_to_int32(sizeof(xStringFeedbackCtl)))
return BadLength;
--
2.31.1
|