From 19599883ffb6a450d2884f081f8ecf68edbed7ee Mon Sep 17 00:00:00 2001
From: Jean Delvare <jdelvare@suse.de>
Date: Thu, 3 May 2018 14:31:55 +0200
Subject: Don't leak temporary file on failed ed-style patch

Now that we write ed-style patches to a temporary file before we
apply them, we need to ensure that the temporary file is removed
before we leave, even on fatal error.

* src/pch.c (do_ed_script): Use global TMPEDNAME instead of local
  tmpname. Don't unlink the file directly, instead tag it for removal
  at exit time.
* src/patch.c (cleanup): Unlink TMPEDNAME at exit.

This closes bug #53820:
https://savannah.gnu.org/bugs/index.php?53820

Fixes: 123eaff0d5d1 ("Fix arbitrary command execution in ed-style patches (CVE-2018-1000156)")
---
 src/common.h |  2 ++
 src/patch.c  |  1 +
 src/pch.c    | 11 +++++------
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/common.h b/src/common.h
index 904a3f8..53c5e32 100644
--- a/src/common.h
+++ b/src/common.h
@@ -94,10 +94,12 @@ XTERN char const *origsuff;
 XTERN char const * TMPINNAME;
 XTERN char const * TMPOUTNAME;
 XTERN char const * TMPPATNAME;
+XTERN char const * TMPEDNAME;
 
 XTERN bool TMPINNAME_needs_removal;
 XTERN bool TMPOUTNAME_needs_removal;
 XTERN bool TMPPATNAME_needs_removal;
+XTERN bool TMPEDNAME_needs_removal;
 
 #ifdef DEBUGGING
 XTERN int debug;
diff --git a/src/patch.c b/src/patch.c
index 3fcaec5..9146597 100644
--- a/src/patch.c
+++ b/src/patch.c
@@ -2003,6 +2003,7 @@ cleanup (void)
   remove_if_needed (TMPINNAME, &TMPINNAME_needs_removal);
   remove_if_needed (TMPOUTNAME, &TMPOUTNAME_needs_removal);
   remove_if_needed (TMPPATNAME, &TMPPATNAME_needs_removal);
+  remove_if_needed (TMPEDNAME, &TMPEDNAME_needs_removal);
   remove_if_needed (TMPREJNAME, &TMPREJNAME_needs_removal);
   output_files (NULL);
 }
diff --git a/src/pch.c b/src/pch.c
index 79a3c99..1bb3153 100644
--- a/src/pch.c
+++ b/src/pch.c
@@ -2392,7 +2392,6 @@ do_ed_script (char const *inname, char c
     file_offset beginning_of_this_line;
     size_t chars_read;
     FILE *tmpfp = 0;
-    char const *tmpname;
     int tmpfd;
     pid_t pid;
 
@@ -2404,12 +2403,13 @@ do_ed_script (char const *inname, char const *outname,
 	   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);
+	tmpfd = make_tempfile (&TMPEDNAME, 'e', NULL, O_RDWR | O_BINARY, 0);
 	if (tmpfd == -1)
-	  pfatal ("Can't create temporary file %s", quotearg (tmpname));
+	  pfatal ("Can't create temporary file %s", quotearg (TMPEDNAME));
+	TMPEDNAME_needs_removal = true;
 	tmpfp = fdopen (tmpfd, "w+b");
 	if (! tmpfp)
-	  pfatal ("Can't open stream for file %s", quotearg (tmpname));
+	  pfatal ("Can't open stream for file %s", quotearg (TMPEDNAME));
       }
 
     for (;;) {
@@ -2449,7 +2449,7 @@ do_ed_script (char const *inname, char c
       write_fatal ();
 
     if (lseek (tmpfd, 0, SEEK_SET) == -1)
-      pfatal ("Can't rewind to the beginning of file %s", quotearg (tmpname));
+      pfatal ("Can't rewind to the beginning of file %s", quotearg (TMPEDNAME));
 
     if (! dry_run && ! skip_rest_of_patch) {
 	int exclusive = *outname_needs_removal ? 0 : O_EXCL;
@@ -2482,7 +2482,6 @@ do_ed_script (char const *inname, char c
     }
 
     fclose (tmpfp);
-    safe_unlink (tmpname);
 
     if (ofp)
       {
-- 
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