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Fix CVE-2016-4024 (integer overflow in lib/image.h).
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-4024
Upstream source:
https://git.enlightenment.org/legacy/imlib2.git/commit/?id=7eba2e4c8ac0e20838947f10f29d0efe1add8227
From 7eba2e4c8ac0e20838947f10f29d0efe1add8227 Mon Sep 17 00:00:00 2001
From: "Yuriy M. Kaminskiy" <yumkam@gmail.com>
Date: Wed, 6 Apr 2016 03:34:01 +0300
Subject: Fix integer overflow resulting in insufficient heap allocation
IMAGE_DIMENSIONS_OK ensures that image width and height are less then
46340, so that maximum number of pixels is ~2**31.
Unfortunately, there are a lot of code that allocates image data with
something like
malloc(w * h * sizeof(DATA32));
Obviously, on 32-bit machines this results in integer overflow,
insufficient heap allocation, with [massive] out-of-bounds heap
overwrite.
Either X_MAX should be reduced to 32767, or (w)*(h) should be checked to
not exceed ULONG_MAX/sizeof(DATA32).
Security implications:
*) for 32-bit machines: insufficient heap allocation and heap overwrite
in many image loaders, with escalation potential to remote code
execution;
*) for 64-bit machines: it seems, no impact.
---
src/lib/image.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/src/lib/image.h b/src/lib/image.h
index e9eb678..5fae6ed 100644
--- a/src/lib/image.h
+++ b/src/lib/image.h
@@ -188,7 +188,8 @@ void __imlib_SaveImage(ImlibImage * im, const char *file,
/* The maximum pixmap dimension is 65535. */
/* However, for now, use 46340 (46340^2 < 2^31) to avoid buffer overflow issues. */
-#define X_MAX_DIM 46340
+/* Reduced further to 32767, so that (w * h * sizeof(DATA32)) won't exceed ULONG_MAX */
+#define X_MAX_DIM 32767
#define IMAGE_DIMENSIONS_OK(w, h) \
( ((w) > 0) && ((h) > 0) && ((w) < X_MAX_DIM) && ((h) < X_MAX_DIM) )
--
cgit v0.12
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