gnu: zsh: Fix CVE-2018-{7548,7549}.

* gnu/packages/patches/zsh-CVE-2018-7548.patch,
gnu/packages/patches/zsh-CVE-2018-7549.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/shells.scm (zsh)[source]: Use them.

gnu/local.mk

@@ -1181,7 +1181,9 @@ dist_patch_DATA =						\
   %D%/packages/patches/xinetd-CVE-2013-4342.patch		\
   %D%/packages/patches/xmodmap-asprintf.patch 			\
   %D%/packages/patches/libyaml-CVE-2014-9130.patch 		\
-  %D%/packages/patches/zathura-plugindir-environment-variable.patch
+  %D%/packages/patches/zathura-plugindir-environment-variable.patch	\
+  %D%/packages/patches/zsh-CVE-2018-7548.patch			\
+  %D%/packages/patches/zsh-CVE-2018-7549.patch
 
 MISC_DISTRO_FILES =				\
   %D%/packages/ld-wrapper.in

gnu/packages/patches/zsh-CVE-2018-7548.patch

@@ -0,0 +1,48 @@
+Fix CVE-2018-7548:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-7548
+
+Patch copied from upstream source repository:
+
+https://sourceforge.net/p/zsh/code/ci/110b13e1090bc31ac1352b28adc2d02b6d25a102
+
+From 110b13e1090bc31ac1352b28adc2d02b6d25a102 Mon Sep 17 00:00:00 2001
+From: Joey Pabalinas <joeypabalinas@gmail.com>
+Date: Tue, 23 Jan 2018 22:28:08 -0800
+Subject: [PATCH] 42313: avoid null-pointer deref when using ${(PA)...} on an
+ empty array result
+
+---
+ ChangeLog   | 5 +++++
+ Src/subst.c | 2 +-
+ 2 files changed, 6 insertions(+), 1 deletion(-)
+
+#diff --git a/ChangeLog b/ChangeLog
+#index d2ba94afc..3037edda4 100644
+#--- a/ChangeLog
+#+++ b/ChangeLog
+#@@ -1,3 +1,8 @@
+#+2018-01-23  Barton E. Schaefer  <schaefer@zsh.org>
+#+
+#+       * Joey Pabalinas: 42313: Src/subst.c: avoid null-pointer deref
+#+       when using ${(PA)...} on an empty array result
+#+
+# 2018-01-23  Oliver Kiddle  <okiddle@yahoo.co.uk>
+# 
+#        * 42317: Completion/Linux/Command/_cryptsetup,
+diff --git a/Src/subst.c b/Src/subst.c
+index d027e3d83..a265a187e 100644
+--- a/Src/subst.c
++++ b/Src/subst.c
+@@ -2430,7 +2430,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
+ 		val = aval[0];
+ 		isarr = 0;
+ 	    }
+-	    s = dyncat(val, s);
++	    s = val ? dyncat(val, s) : dupstring(s);
+ 	    /* Now behave po-faced as if it was always like that... */
+ 	    subexp = 0;
+ 	    /*
+-- 
+2.16.2
+

gnu/packages/patches/zsh-CVE-2018-7549.patch

@@ -0,0 +1,56 @@
+Fix CVE-2018-7549:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-7549
+
+Patch copied from upstream source repository:
+
+https://sourceforge.net/p/zsh/code/ci/c2cc8b0fbefc9868fa83537f5b6d90fc1ec438dd
+
+From c2cc8b0fbefc9868fa83537f5b6d90fc1ec438dd Mon Sep 17 00:00:00 2001
+From: Stephane Chazelas <stephane.chazelas@gmail.com>
+Date: Fri, 22 Dec 2017 22:17:09 +0000
+Subject: [PATCH] Avoid crash copying empty hash table.
+
+Visible with typeset -p.
+---
+ ChangeLog    |  2 ++
+ Src/params.c | 11 +++++++----
+ 2 files changed, 9 insertions(+), 4 deletions(-)
+
+#diff --git a/ChangeLog b/ChangeLog
+#index f74c26b88..e3628cfa7 100644
+#--- a/ChangeLog
+#+++ b/ChangeLog
+#@@ -1,5 +1,7 @@
+# 2018-01-04  Peter Stephenson  <p.stephenson@samsung.com>
+# 
+#+       * Stephane: 42159: Src/params.c: avoid crash copying empty hash table.
+#+
+#        * Sebastian: 42188: Src/Modules/system.c: It is necessary to
+#        close the lock descriptor in some failure cases.
+#
+diff --git a/Src/params.c b/Src/params.c
+index 31ff0445b..de7730ae7 100644
+--- a/Src/params.c
++++ b/Src/params.c
+@@ -549,10 +549,13 @@ scancopyparams(HashNode hn, UNUSED(int flags))
+ HashTable
+ copyparamtable(HashTable ht, char *name)
+ {
+-    HashTable nht = newparamtable(ht->hsize, name);
+-    outtable = nht;
+-    scanhashtable(ht, 0, 0, 0, scancopyparams, 0);
+-    outtable = NULL;
++    HashTable nht = 0;
++    if (ht) {
++	nht = newparamtable(ht->hsize, name);
++	outtable = nht;
++	scanhashtable(ht, 0, 0, 0, scancopyparams, 0);
++	outtable = NULL;
++    }
+     return nht;
+ }
+ 
+-- 
+2.16.2
+

gnu/packages/shells.scm

@@ -300,6 +300,8 @@ (define-public zsh
                          (string-append
                            "http://www.zsh.org/pub/old/zsh-" version
                            ".tar.gz")))
+              (patches (search-patches "zsh-CVE-2018-7548.patch"
+                                       "zsh-CVE-2018-7549.patch"))
               (sha256
                (base32
                 "1jdcfinzmki2w963msvsanv29vqqfmdfm4rncwpw0r3zqnrcsywm"))))