xorg-x11-server/0004-render-Fix-out-of-bounds-access-in-SProcRenderCompos.patch

54 lines
1.6 KiB
Diff

From 35b4681c79480d980bd8dcba390146aad7817c47 Mon Sep 17 00:00:00 2001
From: Povilas Kanapickas <povilas@radix.lt>
Date: Tue, 14 Dec 2021 15:00:03 +0200
Subject: [PATCH xserver 4/4] render: Fix out of bounds access in
SProcRenderCompositeGlyphs()
ZDI-CAN-14192, CVE-2021-4008
This vulnerability was discovered and the fix was suggested by:
Jan-Niklas Sohn working with Trend Micro Zero Day Initiative
Signed-off-by: Povilas Kanapickas <povilas@radix.lt>
(cherry picked from commit ebce7e2d80e7c80e1dda60f2f0bc886f1106ba60)
---
render/render.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/render/render.c b/render/render.c
index c376090ca..456f156d4 100644
--- a/render/render.c
+++ b/render/render.c
@@ -2309,6 +2309,9 @@ SProcRenderCompositeGlyphs(ClientPtr client)
i = elt->len;
if (i == 0xff) {
+ if (buffer + 4 > end) {
+ return BadLength;
+ }
swapl((int *) buffer);
buffer += 4;
}
@@ -2319,12 +2322,18 @@ SProcRenderCompositeGlyphs(ClientPtr client)
buffer += i;
break;
case 2:
+ if (buffer + i * 2 > end) {
+ return BadLength;
+ }
while (i--) {
swaps((short *) buffer);
buffer += 2;
}
break;
case 4:
+ if (buffer + i * 4 > end) {
+ return BadLength;
+ }
while (i--) {
swapl((int *) buffer);
buffer += 4;
--
2.33.1