64 lines
2.2 KiB
Diff
64 lines
2.2 KiB
Diff
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Fix CVE-2017-5896:
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https://bugs.ghostscript.com/show_bug.cgi?id=697515
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https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5896
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http://www.openwall.com/lists/oss-security/2017/02/10/1
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https://security-tracker.debian.org/tracker/CVE-2017-5896
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https://blogs.gentoo.org/ago/2017/02/09/mupdf-use-after-free-in-fz_subsample_pixmap-pixmap-c/
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Patch lifted from upstream source repository:
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http://git.ghostscript.com/?p=mupdf.git;h=2c4e5867ee699b1081527bc6c6ea0e99a35a5c27
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From 2c4e5867ee699b1081527bc6c6ea0e99a35a5c27 Mon Sep 17 00:00:00 2001
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From: Robin Watts <Robin.Watts@artifex.com>
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Date: Thu, 9 Feb 2017 07:12:16 -0800
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Subject: [PATCH] bug 697515: Fix out of bounds read in fz_subsample_pixmap
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Pointer arithmetic for final special case was going wrong.
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---
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source/fitz/pixmap.c | 6 ++++--
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1 file changed, 4 insertions(+), 2 deletions(-)
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diff --git a/source/fitz/pixmap.c b/source/fitz/pixmap.c
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index a8317127..f1291dc2 100644
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--- a/source/fitz/pixmap.c
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+++ b/source/fitz/pixmap.c
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@@ -1104,6 +1104,7 @@ fz_subsample_pixmap_ARM(unsigned char *ptr, int w, int h, int f, int factor,
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"@STACK:r1,<9>,factor,n,fwd,back,back2,fwd2,divX,back4,fwd4,fwd3,divY,back5,divXY\n"
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"ldr r4, [r13,#4*22] @ r4 = divXY \n"
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"ldr r5, [r13,#4*11] @ for (nn = n; nn > 0; n--) { \n"
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+ "ldr r8, [r13,#4*17] @ r8 = back4 \n"
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"18: @ \n"
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"mov r14,#0 @ r14= v = 0 \n"
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"sub r5, r5, r1, LSL #8 @ for (xx = x; xx > 0; x--) { \n"
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@@ -1120,7 +1121,7 @@ fz_subsample_pixmap_ARM(unsigned char *ptr, int w, int h, int f, int factor,
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"mul r14,r4, r14 @ r14= v *= divX \n"
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"mov r14,r14,LSR #16 @ r14= v >>= 16 \n"
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"strb r14,[r9], #1 @ *d++ = r14 \n"
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- "sub r0, r0, r8 @ s -= back2 \n"
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+ "sub r0, r0, r8 @ s -= back4 \n"
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"subs r5, r5, #1 @ n-- \n"
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"bgt 18b @ } \n"
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"21: @ \n"
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@@ -1249,6 +1250,7 @@ fz_subsample_pixmap(fz_context *ctx, fz_pixmap *tile, int factor)
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x += f;
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if (x > 0)
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{
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+ int back4 = x * n - 1;
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div = x * y;
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for (nn = n; nn > 0; nn--)
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{
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@@ -1263,7 +1265,7 @@ fz_subsample_pixmap(fz_context *ctx, fz_pixmap *tile, int factor)
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s -= back5;
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}
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*d++ = v / div;
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- s -= back2;
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+ s -= back4;
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}
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}
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}
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--
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2.12.0
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