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/packages/pdf.scm (mupdf/fixed)[source]: Add patches.
* gnu/local.mk (dist_patch_DATA): Add them.

Signed-off-by: Leo Famulari <leo@famulari.name>

1 files changed, 101 insertions, 0 deletions

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 0000000000..1fa6dc3466
--- /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 <robin.watts@artifex.com>
+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
+