ghostscript/ghostscript-9.23-000-CVE-2018-10194.patch

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From 39b1e54b2968620723bf32e96764c88797714879 Mon Sep 17 00:00:00 2001
From: Ken Sharp <ken.sharp@artifex.com>
Date: Wed, 18 Apr 2018 15:46:32 +0100
Subject: [PATCH] pdfwrite - Guard against trying to output an infinite number
Bug #699255 " Buffer overflow on pprintg1 due to mishandle postscript file data to pdf"
The file uses an enormous parameter to xyxhow, causing an overflow in
the calculation of text positioning (value > 1e39).
Since this is basically a nonsense value, and PostScript only supports
real values up to 1e38, this patch follows the same approach as for
a degenerate CTM, and treats it as 0.
Adobe Acrobat Distiller throws a limitcheck error, so we could do that
instead if this approach proves to be a problem.
---
devices/vector/gdevpdts.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/devices/vector/gdevpdts.c b/devices/vector/gdevpdts.c
index 848ad781f..172fe6bc3 100644
--- a/devices/vector/gdevpdts.c
+++ b/devices/vector/gdevpdts.c
@@ -103,9 +103,14 @@ append_text_move(pdf_text_state_t *pts, double dw)
static int
set_text_distance(gs_point *pdist, double dx, double dy, const gs_matrix *pmat)
{
- int code = gs_distance_transform_inverse(dx, dy, pmat, pdist);
+ int code;
double rounded;
+ if (dx > 1e38 || dy > 1e38)
+ code = gs_error_undefinedresult;
+ else
+ code = gs_distance_transform_inverse(dx, dy, pmat, pdist);
+
if (code == gs_error_undefinedresult) {
/* The CTM is degenerate.
Can't know the distance in user space.
--
2.14.3