Subject: bug#25935: [PATCH] gnu: mupdf: Fix CVE-2017-{5896,5991}.

From: Alex Vong <[email-masked]>
Date: Thu, 02 Mar 2017 21:15:29 +0800

I've just found out we have guix-patches now! We should continue the
discussion in the bug report instead of guix-devel.

Subject: [PATCH] gnu: mupdf: Fix CVE-2017-{5896,5991}.
From: Alex Vong <[email-masked]>
To: [email-masked]
Date: Thu, 02 Mar 2017 20:55:25 +0800

Hello,

This patch (applied to core-updates) fixes the two CVEs disclosed recently.

I am currently testing the patch. I think the patch works but it is
still building right now.

From a5bb1e9601d8bb3e48fdb521e6d1821dd5d9c833 Mon Sep 17 00:00:00 2001
From: Alex Vong <[email-masked]>
Date: Thu, 2 Mar 2017 19:59:05 +0800
Subject: [PATCH] gnu: mupdf: Fix CVE-2017-{5896,5991}.

* gnu/packages/patches/mupdf-CVE-2017-5896.patch,
gnu/packages/patches/mupdf-CVE-2017-5991.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/pdf.scm (mupdf)[source]: Use it.
---
 gnu/local.mk                                   |   2 +
 gnu/packages/patches/mupdf-CVE-2017-5896.patch |  63 +++++++++++++++
 gnu/packages/patches/mupdf-CVE-2017-5991.patch | 101 +++++++++++++++++++++++++
 gnu/packages/pdf.scm                           |   5 +-
 4 files changed, 170 insertions(+), 1 deletion(-)
 create mode 100644 gnu/packages/patches/mupdf-CVE-2017-5896.patch
 create mode 100644 gnu/packages/patches/mupdf-CVE-2017-5991.patch

diff --git a/gnu/local.mk b/gnu/local.mk
index 3d9ad7065..d0ec9ea50 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -767,6 +767,8 @@ dist_patch_DATA =						\
   %D%/packages/patches/mupdf-build-with-openjpeg-2.1.patch	\
   %D%/packages/patches/mupdf-mujs-CVE-2016-10132.patch		\
   %D%/packages/patches/mupdf-mujs-CVE-2016-10133.patch		\
+  %D%/packages/patches/mupdf-CVE-2017-5896.patch		\
+  %D%/packages/patches/mupdf-CVE-2017-5991.patch		\
   %D%/packages/patches/mupen64plus-ui-console-notice.patch	\
   %D%/packages/patches/musl-CVE-2016-8859.patch			\
   %D%/packages/patches/mutt-store-references.patch		\
diff --git a/gnu/packages/patches/mupdf-CVE-2017-5896.patch b/gnu/packages/patches/mupdf-CVE-2017-5896.patch
new file mode 100644
index 000000000..1537ecc89
--- /dev/null
+++ b/gnu/packages/patches/mupdf-CVE-2017-5896.patch
@@ -0,0 +1,63 @@
+Fix CVE-2017-5896:
+
+https://bugs.ghostscript.com/show_bug.cgi?id=697515
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5896
+http://www.openwall.com/lists/oss-security/2017/02/10/1
+https://security-tracker.debian.org/tracker/CVE-2017-5896
+https://blogs.gentoo.org/ago/2017/02/09/mupdf-use-after-free-in-fz_subsample_pixmap-pixmap-c/
+
+Patch lifted from upstream source repository:
+
+http://git.ghostscript.com/?p=mupdf.git;h=2c4e5867ee699b1081527bc6c6ea0e99a35a5c27
+
+From 2c4e5867ee699b1081527bc6c6ea0e99a35a5c27 Mon Sep 17 00:00:00 2001
+From: Robin Watts <[email-masked]>
+Date: Thu, 9 Feb 2017 07:12:16 -0800
+Subject: [PATCH] bug 697515: Fix out of bounds read in fz_subsample_pixmap
+
+Pointer arithmetic for final special case was going wrong.
+---
+ source/fitz/pixmap.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/source/fitz/pixmap.c b/source/fitz/pixmap.c
+index a8317127..f1291dc2 100644
+--- a/source/fitz/pixmap.c
++++ b/source/fitz/pixmap.c
+@@ -1104,6 +1104,7 @@ fz_subsample_pixmap_ARM(unsigned char *ptr, int w, int h, int f, int factor,
+ 	"@STACK:r1,<9>,factor,n,fwd,back,back2,fwd2,divX,back4,fwd4,fwd3,divY,back5,divXY\n"
+ 	"ldr	r4, [r13,#4*22]		@ r4 = divXY			\n"
+ 	"ldr	r5, [r13,#4*11]		@ for (nn = n; nn > 0; n--) {	\n"
++	"ldr	r8, [r13,#4*17]		@ r8 = back4			\n"
+ 	"18:				@				\n"
+ 	"mov	r14,#0			@ r14= v = 0			\n"
+ 	"sub	r5, r5, r1, LSL #8	@ for (xx = x; xx > 0; x--) {	\n"
+@@ -1120,7 +1121,7 @@ fz_subsample_pixmap_ARM(unsigned char *ptr, int w, int h, int f, int factor,
+ 	"mul	r14,r4, r14		@ r14= v *= divX		\n"
+ 	"mov	r14,r14,LSR #16		@ r14= v >>= 16			\n"
+ 	"strb	r14,[r9], #1		@ *d++ = r14			\n"
+-	"sub	r0, r0, r8		@ s -= back2			\n"
++	"sub	r0, r0, r8		@ s -= back4			\n"
+ 	"subs	r5, r5, #1		@ n--				\n"
+ 	"bgt	18b			@ }				\n"
+ 	"21:				@				\n"
+@@ -1249,6 +1250,7 @@ fz_subsample_pixmap(fz_context *ctx, fz_pixmap *tile, int factor)
+ 		x += f;
+ 		if (x > 0)
+ 		{
++			int back4 = x * n - 1;
+ 			div = x * y;
+ 			for (nn = n; nn > 0; nn--)
+ 			{
+@@ -1263,7 +1265,7 @@ fz_subsample_pixmap(fz_context *ctx, fz_pixmap *tile, int factor)
+ 					s -= back5;
+ 				}
+ 				*d++ = v / div;
+-				s -= back2;
++				s -= back4;
+ 			}
+ 		}
+ 	}
+-- 
+2.12.0
+
diff --git a/gnu/packages/patches/mupdf-CVE-2017-5991.patch b/gnu/packages/patches/mupdf-CVE-2017-5991.patch
new file mode 100644
index 000000000..1fa6dc346
--- /dev/null
+++ b/gnu/packages/patches/mupdf-CVE-2017-5991.patch
@@ -0,0 +1,101 @@
+Fix CVE-2017-5991:
+
+https://bugs.ghostscript.com/show_bug.cgi?id=697500
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-5991
+https://security-tracker.debian.org/tracker/CVE-2017-5991
+
+Patch lifted from upstream source repository:
+
+http://git.ghostscript.com/?p=mupdf.git;h=1912de5f08e90af1d9d0a9791f58ba3afdb9d465
+
+From 1912de5f08e90af1d9d0a9791f58ba3afdb9d465 Mon Sep 17 00:00:00 2001
+From: Robin Watts <[email-masked]>
+Date: Thu, 9 Feb 2017 15:49:15 +0000
+Subject: [PATCH] Bug 697500: Fix NULL ptr access.
+
+Cope better with errors during rendering - avoid letting the
+gstate stack get out of sync.
+
+This avoids us ever getting into the situation of popping
+a clip when we should be popping a mask or a group. This was
+causing an unexpected case in the painting.
+---
+ source/pdf/pdf-op-run.c | 26 ++++++++++++++++++--------
+ 1 file changed, 18 insertions(+), 8 deletions(-)
+
+diff --git a/source/pdf/pdf-op-run.c b/source/pdf/pdf-op-run.c
+index a3ea895d..f1eac8d3 100644
+--- a/source/pdf/pdf-op-run.c
++++ b/source/pdf/pdf-op-run.c
+@@ -1213,6 +1213,7 @@ pdf_run_xobject(fz_context *ctx, pdf_run_processor *proc, pdf_xobject *xobj, pdf
+ 	pdf_run_processor *pr = (pdf_run_processor *)proc;
+ 	pdf_gstate *gstate = NULL;
+ 	int oldtop = 0;
++	int oldbot = -1;
+ 	fz_matrix local_transform = *transform;
+ 	softmask_save softmask = { NULL };
+ 	int gparent_save;
+@@ -1232,16 +1233,17 @@ pdf_run_xobject(fz_context *ctx, pdf_run_processor *proc, pdf_xobject *xobj, pdf
+ 	fz_var(cleanup_state);
+ 	fz_var(gstate);
+ 	fz_var(oldtop);
++	fz_var(oldbot);
+ 
+ 	gparent_save = pr->gparent;
+ 	pr->gparent = pr->gtop;
++	oldtop = pr->gtop;
+ 
+ 	fz_try(ctx)
+ 	{
+ 		pdf_gsave(ctx, pr);
+ 
+ 		gstate = pr->gstate + pr->gtop;
+-		oldtop = pr->gtop;
+ 
+ 		pdf_xobject_bbox(ctx, xobj, &xobj_bbox);
+ 		pdf_xobject_matrix(ctx, xobj, &xobj_matrix);
+@@ -1302,12 +1304,25 @@ pdf_run_xobject(fz_context *ctx, pdf_run_processor *proc, pdf_xobject *xobj, pdf
+ 
+ 		doc = pdf_get_bound_document(ctx, xobj->obj);
+ 
++		oldbot = pr->gbot;
++		pr->gbot = pr->gtop;
++
+ 		pdf_process_contents(ctx, (pdf_processor*)pr, doc, resources, xobj->obj, NULL);
+ 	}
+ 	fz_always(ctx)
+ 	{
++		/* Undo any gstate mismatches due to the pdf_process_contents call */
++		if (oldbot != -1)
++		{
++			while (pr->gtop > pr->gbot)
++			{
++				pdf_grestore(ctx, pr);
++			}
++			pr->gbot = oldbot;
++		}
++
+ 		if (cleanup_state >= 3)
+-			pdf_grestore(ctx, pr); /* Remove the clippath */
++			pdf_grestore(ctx, pr); /* Remove the state we pushed for the clippath */
+ 
+ 		/* wrap up transparency stacks */
+ 		if (transparency)
+@@ -1341,13 +1356,8 @@ pdf_run_xobject(fz_context *ctx, pdf_run_processor *proc, pdf_xobject *xobj, pdf
+ 		pr->gstate[pr->gparent].ctm = gparent_save_ctm;
+ 		pr->gparent = gparent_save;
+ 
+-		if (gstate)
+-		{
+-			while (oldtop < pr->gtop)
+-				pdf_grestore(ctx, pr);
+-
++		while (oldtop < pr->gtop)
+ 			pdf_grestore(ctx, pr);
+-		}
+ 
+ 		pdf_unmark_obj(ctx, xobj->obj);
+ 	}
+-- 
+2.12.0
+
diff --git a/gnu/packages/pdf.scm b/gnu/packages/pdf.scm
index d449b72ee..205b8af2d 100644
--- a/gnu/packages/pdf.scm
+++ b/gnu/packages/pdf.scm
@@ -11,6 +11,7 @@
 ;;; Coypright © 2016 Julien Lepiller <[email-masked]>
 ;;; Copyright © 2016 Arun Isaac <[email-masked]>
 ;;; Copyright © 2017 Leo Famulari <[email-masked]>
+;;; Copyright © 2017 Alex Vong <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -492,7 +493,9 @@ extracting content or merging files.")
           "0dm8wcs8i29aibzkqkrn8kcnk4q0kd1v66pg48h5c3qqp4v1zk5a"))
         (patches (search-patches "mupdf-build-with-openjpeg-2.1.patch"
                                  "mupdf-mujs-CVE-2016-10132.patch"
-                                 "mupdf-mujs-CVE-2016-10133.patch"))
+                                 "mupdf-mujs-CVE-2016-10133.patch"
+                                 "mupdf-CVE-2017-5896.patch"
+                                 "mupdf-CVE-2017-5991.patch"))
         (modules '((guix build utils)))
         (snippet
             ;; Delete all the bundled libraries except for mujs, which is
-- 
2.12.0

Cheers,
Alex