From d74a30d45c6834c8e9f87115197370fe86656d81 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering@fb.com>
Date: Mon, 4 Apr 2022 23:52:49 -0700
Subject: zgrep: add NEWS and tests for this exploitable bug

* tests/zgrep-abuse: New file, based on PoC by cleemy desu wayo.
* tests/Makefile.am (TESTS): Add it.
* NEWS: Mention the exploit.
The bug appears to have been present since the beginning.
---
 tests/Makefile.am |  1 +
 tests/zgrep-abuse | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 42 insertions(+)
 create mode 100755 tests/zgrep-abuse

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 18e7c8a..28a1828 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -36,6 +36,7 @@ TESTS =					\
   z-suffix				\
   zdiff					\
   zgrep-f				\
+  zgrep-abuse				\
   zgrep-context				\
   zgrep-signal				\
   znew-k
diff --git a/tests/zgrep-abuse b/tests/zgrep-abuse
new file mode 100755
index 0000000..3e8a8f9
--- /dev/null
+++ b/tests/zgrep-abuse
@@ -0,0 +1,41 @@
+#!/bin/sh
+# Show how zgrep applied to a crafted file name may overwrite
+# a selected file with chosen content.  Fixed in gzip-1.12.
+
+# Copyright (C) 2022 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+# limit so don't run it by default.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ..
+
+: > z || framework_failure_
+echo test |gzip > 'z|
+p
+1s|.*|chosen-content|
+1w hacked
+etouch .\x2fhacked2
+d
+#
+#' || framework_failure_
+
+fail=0
+
+zgrep test z* > /dev/null
+
+# Before the fix, each of these would be created.
+test -f hacked && fail=1
+test -f hacked2 && fail=1
+
+Exit $fail
-- 
1.8.3.1