gnu: mupdf: Fix CVE-2018-{6544,1000051}.

* gnu/packages/patches/mupdf-CVE-2018-1000051.patch,
gnu/packages/patches/mupdf-CVE-2018-6544.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/pdf.scm (mupdf)[source]: Use them.

1 files changed, 109 insertions, 0 deletions

diff --git a/gnu/packages/patches/mupdf-CVE-2018-6544.patch b/gnu/packages/patches/mupdf-CVE-2018-6544.patch
new file mode 100644
index 0000000000..b2c8f849f3
--- /dev/null
+++ b/gnu/packages/patches/mupdf-CVE-2018-6544.patch
@@ -0,0 +1,109 @@
+Fix CVE-2018-6544:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6544
+https://bugs.ghostscript.com/show_bug.cgi?id=698830
+https://bugs.ghostscript.com/show_bug.cgi?id=698965 
+
+Patches copied from upstream source repository:
+
+https://git.ghostscript.com/?p=mupdf.git;h=26527eef77b3e51c2258c8e40845bfbc015e405d
+https://git.ghostscript.com/?p=mupdf.git;h=b03def134988da8c800adac1a38a41a1f09a1d89
+
+From b03def134988da8c800adac1a38a41a1f09a1d89 Mon Sep 17 00:00:00 2001
+From: Sebastian Rasmussen <sebras@gmail.com>
+Date: Thu, 1 Feb 2018 16:36:14 +0100
+Subject: [PATCH] Bug 698830: Avoid recursion when loading object streams
+ objects.
+
+If there were indirect references in the object stream dictionary and
+one of those indirect references referred to an object inside the object
+stream itself, mupdf would previously enter recursion only bounded by the
+exception stack. After this commit the object stream is checked if it is
+marked immediately after being loaded. If it is marked then we terminate
+the recursion at this point, if it is not marked then mark it and
+attempt to load the desired object within. We also take care to unmark
+the stream object when done or upon exception.
+---
+ source/pdf/pdf-xref.c | 14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+
+diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c
+index 723b543c..ed09094c 100644
+--- a/source/pdf/pdf-xref.c
++++ b/source/pdf/pdf-xref.c
+@@ -1576,6 +1576,19 @@ pdf_load_obj_stm(fz_context *ctx, pdf_document *doc, int num, pdf_lexbuf *buf, i
+ 	{
+ 		objstm = pdf_load_object(ctx, doc, num);
+ 
++		if (pdf_obj_marked(ctx, objstm))
++			fz_throw(ctx, FZ_ERROR_GENERIC, "recursive object stream lookup");
++	}
++	fz_catch(ctx)
++	{
++		pdf_drop_obj(ctx, objstm);
++		fz_rethrow(ctx);
++	}
++
++	fz_try(ctx)
++	{
++		pdf_mark_obj(ctx, objstm);
++
+ 		count = pdf_to_int(ctx, pdf_dict_get(ctx, objstm, PDF_NAME_N));
+ 		first = pdf_to_int(ctx, pdf_dict_get(ctx, objstm, PDF_NAME_First));
+ 
+@@ -1655,6 +1668,7 @@ pdf_load_obj_stm(fz_context *ctx, pdf_document *doc, int num, pdf_lexbuf *buf, i
+ 		fz_drop_stream(ctx, stm);
+ 		fz_free(ctx, ofsbuf);
+ 		fz_free(ctx, numbuf);
++		pdf_unmark_obj(ctx, objstm);
+ 		pdf_drop_obj(ctx, objstm);
+ 	}
+ 	fz_catch(ctx)
+-- 
+2.16.3
+
+From 26527eef77b3e51c2258c8e40845bfbc015e405d Mon Sep 17 00:00:00 2001
+From: Sebastian Rasmussen <sebras@gmail.com>
+Date: Mon, 29 Jan 2018 02:00:48 +0100
+Subject: [PATCH] Bug 698830: Don't drop unkept stream if running out of error
+ stack.
+
+Under normal conditions where fz_keep_stream() is called inside
+fz_try() we may call fz_drop_stream() in fz_catch() upon exceptions.
+The issue comes when fz_keep_stream() has not yet been called but is
+dropped in fz_catch(). This happens in the PDF from the bug when
+fz_try() runs out of exception stack, and next the code in fz_catch()
+runs, dropping the caller's reference to the filter chain stream!
+
+The simplest way of fixing this it to always keep the filter chain
+stream before fz_try() is called. That way fz_catch() may drop the
+stream whether an exception has occurred or if the fz_try() ran out of
+exception stack.
+---
+ source/pdf/pdf-stream.c | 5 ++---
+ 1 file changed, 2 insertions(+), 3 deletions(-)
+
+diff --git a/source/pdf/pdf-stream.c b/source/pdf/pdf-stream.c
+index c89da5c4..c6ba7ad3 100644
+--- a/source/pdf/pdf-stream.c
++++ b/source/pdf/pdf-stream.c
+@@ -303,14 +303,13 @@ pdf_open_raw_filter(fz_context *ctx, fz_stream *chain, pdf_document *doc, pdf_ob
+ 		*orig_gen = 0;
+ 	}
+ 
+-	fz_var(chain);
++	chain = fz_keep_stream(ctx, chain);
+ 
+ 	fz_try(ctx)
+ 	{
+ 		len = pdf_to_int(ctx, pdf_dict_get(ctx, stmobj, PDF_NAME_Length));
+ 
+-		/* don't close chain when we close this filter */
+-		chain2 = fz_keep_stream(ctx, chain);
++		chain2 = chain;
+ 		chain = NULL;
+ 		chain = fz_open_null(ctx, chain2, len, offset);
+ 
+-- 
+2.16.3
+