gnu: libpng: Fix a null pointer dereference [fixes security issue].

* gnu/packages/patches/libpng-fix-null-ptr-dereference.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/image.scm (libpng)[replacement]: New field.
(libpng/fixed): New variable.

1 files changed, 36 insertions, 0 deletions

diff --git a/gnu/packages/patches/libpng-fix-null-ptr-dereference.patch b/gnu/packages/patches/libpng-fix-null-ptr-dereference.patch
new file mode 100644
index 0000000000..192459162b
--- /dev/null
+++ b/gnu/packages/patches/libpng-fix-null-ptr-dereference.patch
@@ -0,0 +1,36 @@
+Fix a null pointer dereference in png_set_text_2():
+
+http://seclists.org/oss-sec/2016/q4/777
+
+Patch adapted from upstream source repository:
+
+https://sourceforge.net/p/libpng/code/ci/812768d7a9c973452222d454634496b25ed415eb/
+
+From 812768d7a9c973452222d454634496b25ed415eb Mon Sep 17 00:00:00 2001
+From: Glenn Randers-Pehrson <glennrp at users.sourceforge.net>
+Date: Thu, 29 Dec 2016 07:51:33 -0600
+Subject: [PATCH] [libpng16] Fixed a potential null pointer dereference in
+ png_set_text_2()
+
+(bug report and patch by Patrick Keshishian).
+---
+ ANNOUNCE | 2 ++
+ CHANGES  | 2 ++
+ png.c    | 1 +
+ 3 files changed, 5 insertions(+)
+
+diff --git a/png.c b/png.c
+index 8afc28fc2..2e05de159 100644
+--- a/png.c
++++ b/png.c
+@@ -477,6 +477,7 @@ png_free_data(png_const_structrp png_ptr, png_inforp info_ptr, png_uint_32 mask,
+          png_free(png_ptr, info_ptr->text);
+          info_ptr->text = NULL;
+          info_ptr->num_text = 0;
++         info_ptr->max_text = 0;
+       }
+    }
+ #endif
+-- 
+2.11.0
+