From 3aad41012c857e1ba205cb2200b5c05e320ded58 Mon Sep 17 00:00:00 2001
From: Tim Waugh <twaugh@redhat.com>
Date: May 03 2018 11:53:39 +0000
Subject: Fixed CVE-2018-1000156 - Malicious patch files cause ed to execute arbitrary commands.


---

diff --git a/patch-CVE-2018-1000156.patch b/patch-CVE-2018-1000156.patch
new file mode 100644
index 0000000..fc3b0c2
--- /dev/null
+++ b/patch-CVE-2018-1000156.patch
@@ -0,0 +1,209 @@
+diff -up patch-2.7.6/src/pch.c.CVE-2018-1000156 patch-2.7.6/src/pch.c
+--- patch-2.7.6/src/pch.c.CVE-2018-1000156	2018-02-03 12:41:49.000000000 +0000
++++ patch-2.7.6/src/pch.c	2018-05-03 12:50:43.374036905 +0100
+@@ -33,6 +33,7 @@
+ # include <io.h>
+ #endif
+ #include <safe.h>
++#include <sys/wait.h>
+ 
+ #define INITHUNKMAX 125			/* initial dynamic allocation size */
+ 
+@@ -2388,22 +2389,28 @@ do_ed_script (char const *inname, char c
+     static char const editor_program[] = EDITOR_PROGRAM;
+ 
+     file_offset beginning_of_this_line;
+-    FILE *pipefp = 0;
+     size_t chars_read;
++    FILE *tmpfp = 0;
++    char const *tmpname;
++    int tmpfd = -1;
++    pid_t pid;
++
++    if (! dry_run && ! skip_rest_of_patch)
++      {
++       /* Write ed script to a temporary file.  This causes ed to abort on
++          invalid commands such as when line numbers or ranges exceed the
++          number of available lines.  When ed reads from a pipe, it rejects
++          invalid commands and treats the next line as a new command, which
++          can lead to arbitrary command execution.  */
++
++       tmpfd = make_tempfile (&tmpname, 'e', NULL, O_RDWR | O_BINARY, 0);
++       if (tmpfd == -1)
++         pfatal ("Can't create temporary file %s", quotearg (tmpname));
++       tmpfp = fdopen (tmpfd, "w+b");
++       if (! tmpfp)
++         pfatal ("Can't open stream for file %s", quotearg (tmpname));
++      }
+ 
+-    if (! dry_run && ! skip_rest_of_patch) {
+-	int exclusive = *outname_needs_removal ? 0 : O_EXCL;
+-	assert (! inerrno);
+-	*outname_needs_removal = true;
+-	copy_file (inname, outname, 0, exclusive, instat.st_mode, true);
+-	sprintf (buf, "%s %s%s", editor_program,
+-		 verbosity == VERBOSE ? "" : "- ",
+-		 outname);
+-	fflush (stdout);
+-	pipefp = popen(buf, binary_transput ? "wb" : "w");
+-	if (!pipefp)
+-	  pfatal ("Can't open pipe to %s", quotearg (buf));
+-    }
+     for (;;) {
+ 	char ed_command_letter;
+ 	beginning_of_this_line = file_tell (pfp);
+@@ -2414,14 +2421,14 @@ do_ed_script (char const *inname, char c
+ 	}
+ 	ed_command_letter = get_ed_command_letter (buf);
+ 	if (ed_command_letter) {
+-	    if (pipefp)
+-		if (! fwrite (buf, sizeof *buf, chars_read, pipefp))
++	    if (tmpfp)
++		if (! fwrite (buf, sizeof *buf, chars_read, tmpfp))
+ 		    write_fatal ();
+ 	    if (ed_command_letter != 'd' && ed_command_letter != 's') {
+ 	        p_pass_comments_through = true;
+ 		while ((chars_read = get_line ()) != 0) {
+-		    if (pipefp)
+-			if (! fwrite (buf, sizeof *buf, chars_read, pipefp))
++		    if (tmpfp)
++			if (! fwrite (buf, sizeof *buf, chars_read, tmpfp))
+ 			    write_fatal ();
+ 		    if (chars_read == 2  &&  strEQ (buf, ".\n"))
+ 			break;
+@@ -2434,13 +2441,50 @@ do_ed_script (char const *inname, char c
+ 	    break;
+ 	}
+     }
+-    if (!pipefp)
++    if (!tmpfp)
+       return;
+-    if (fwrite ("w\nq\n", sizeof (char), (size_t) 4, pipefp) == 0
+-	|| fflush (pipefp) != 0)
++    if (fwrite ("w\nq\n", sizeof (char), (size_t) 4, tmpfp) == 0
++	|| fflush (tmpfp) != 0)
+       write_fatal ();
+-    if (pclose (pipefp) != 0)
+-      fatal ("%s FAILED", editor_program);
++
++    if (lseek (tmpfd, 0, SEEK_SET) == -1)
++      pfatal ("Can't rewind to the beginning of file %s", quotearg (tmpname));
++
++    if (! dry_run && ! skip_rest_of_patch) {
++       int exclusive = *outname_needs_removal ? 0 : O_EXCL;
++       *outname_needs_removal = true;
++       if (inerrno != ENOENT)
++         {
++           *outname_needs_removal = true;
++           copy_file (inname, outname, 0, exclusive, instat.st_mode, true);
++         }
++       sprintf (buf, "%s %s%s", editor_program,
++                verbosity == VERBOSE ? "" : "- ",
++                outname);
++       fflush (stdout);
++
++       pid = fork();
++       if (pid == -1)
++         pfatal ("Can't fork");
++       else if (pid == 0)
++         {
++           dup2 (tmpfd, 0);
++           execl ("/bin/sh", "sh", "-c", buf, (char *) 0);
++           _exit (2);
++         }
++       else
++         {
++           int wstatus;
++           if (waitpid (pid, &wstatus, 0) == -1
++               || ! WIFEXITED (wstatus)
++               || WEXITSTATUS (wstatus) != 0)
++             fatal ("%s FAILED", editor_program);
++         }
++    }
++
++    fclose (tmpfp);
++    unlink (tmpname);
++    free((char*) tmpname);
+ 
+     if (ofp)
+       {
+diff -up patch-2.7.6/tests/ed-style.CVE-2018-1000156 patch-2.7.6/tests/ed-style
+--- patch-2.7.6/tests/ed-style.CVE-2018-1000156	2018-05-03 12:50:28.988937938 +0100
++++ patch-2.7.6/tests/ed-style	2018-05-03 12:51:35.841397873 +0100
+@@ -0,0 +1,40 @@
++# Copyright (C) 2018 Free Software Foundation, Inc.
++#
++# Copying and distribution of this file, with or without modification,
++# in any medium, are permitted without royalty provided the copyright
++# notice and this notice are preserved.
++
++. $srcdir/test-lib.sh
++
++require_cat
++use_local_patch
++use_tmpdir
++
++# ==============================================================
++
++cat > ed1.diff <<EOF
++0a
++foo
++.
++EOF
++
++check 'patch -e foo -i ed1.diff' <<EOF
++EOF
++
++check 'cat foo' <<EOF
++foo
++EOF
++
++cat > ed2.diff <<EOF
++1337a
++r !echo bar
++,p
++EOF
++
++check 'patch -e foo -i ed2.diff > /dev/null 2> /dev/null || echo "Status: $?"' <<EOF
++Status: 2
++EOF
++
++check 'cat foo' <<EOF
++foo
++EOF
+diff -up patch-2.7.6/tests/Makefile.am.CVE-2018-1000156 patch-2.7.6/tests/Makefile.am
+--- patch-2.7.6/tests/Makefile.am.CVE-2018-1000156	2018-05-03 12:50:28.988937938 +0100
++++ patch-2.7.6/tests/Makefile.am	2018-05-03 12:50:57.340132989 +0100
+@@ -32,6 +32,7 @@ TESTS = \
+ 	crlf-handling \
+ 	dash-o-append \
+ 	deep-directories \
++	ed-style \
+ 	empty-files \
+ 	false-match \
+ 	fifo \
+diff -up patch-2.7.6/tests/Makefile.in.CVE-2018-1000156 patch-2.7.6/tests/Makefile.in
+--- patch-2.7.6/tests/Makefile.in.CVE-2018-1000156	2018-05-03 12:50:28.989937944 +0100
++++ patch-2.7.6/tests/Makefile.in	2018-05-03 12:51:25.974329992 +0100
+@@ -1308,6 +1308,7 @@ TESTS = \
+ 	crlf-handling \
+ 	dash-o-append \
+ 	deep-directories \
++	ed-style \
+ 	empty-files \
+ 	false-match \
+ 	fifo \
+@@ -1645,6 +1646,13 @@ empty-files.log: empty-files
+ 	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
+ 	--log-file $$b.log --trs-file $$b.trs \
+ 	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
++	"$$tst" $(AM_TESTS_FD_REDIRECT)
++ed-style.log: empty-files
++	@p='ed-style'; \
++	b='ed-style'; \
++	$(am__check_pre) $(LOG_DRIVER) --test-name "$$f" \
++	--log-file $$b.log --trs-file $$b.trs \
++	$(am__common_driver_flags) $(AM_LOG_DRIVER_FLAGS) $(LOG_DRIVER_FLAGS) -- $(LOG_COMPILE) \
+ 	"$$tst" $(AM_TESTS_FD_REDIRECT)
+ false-match.log: false-match
+ 	@p='false-match'; \
diff --git a/patch.spec b/patch.spec
index 1ab1b43..5fd438d 100644
--- a/patch.spec
+++ b/patch.spec
@@ -1,11 +1,12 @@
 Summary: Utility for modifying/upgrading files
 Name: patch
 Version: 2.7.6
-Release: 3%{?dist}
+Release: 4%{?dist}
 License: GPLv3+
 URL: http://www.gnu.org/software/patch/patch.html
 Group: Development/Tools
 Source: ftp://ftp.gnu.org/gnu/patch/patch-%{version}.tar.xz
+Patch1: patch-CVE-2018-1000156.patch
 Patch100: patch-selinux.patch
 Buildroot: %{_tmppath}/%{name}-%{version}-%{release}-root-%(%{__id_u} -n)
 
@@ -26,6 +27,9 @@ applications.
 %prep
 %setup -q
 
+# CVE-2018-1000156, Malicious patch files cause ed to execute arbitrary commands
+%patch1 -p1 -b .CVE-2018-1000156
+
 # SELinux support.
 %patch100 -p1 -b .selinux
 
@@ -52,6 +56,10 @@ rm -rf $RPM_BUILD_ROOT
 %{_mandir}/*/*
 
 %changelog
+* Thu May  3 2018 Tim Waugh <twaugh@redhat.com> - 2.7.6-4
+- Fixed CVE-2018-1000156 - Malicious patch files cause ed to execute arbitrary
+  commands.
+
 * Mon Feb 12 2018 Tim Waugh <twaugh@redhat.com> - 2.7.6-3
 - 2.7.6 (CVE-2016-10713, CVE-2018-6951, CVE-2018-6952).