support: Prevent multiple deletion of temporary files

Otherwise, another user might recreate these files after the first
deletion.  Particularly with temporary directories, this could result
in the removal of unintended files through symbol link attacks.

4 files changed, 45 insertions, 88 deletions

diff --git a/posix/tst-exec.c b/posix/tst-exec.c
index be0114e1f9..12a0f57114 100644
--- a/posix/tst-exec.c
+++ b/posix/tst-exec.c
@@ -47,6 +47,10 @@ extern int do_test (int argc, char *argv[]);
 static char *name1;
 static char *name2;
 
+/* File descriptors for these temporary files.  */
+static int temp_fd1 = -1;
+static int temp_fd2 = -1;
+
 /* The contents of our files.  */
 static const char fd1string[] = "This file should get closed";
 static const char fd2string[] = "This file should stay opened";
@@ -56,18 +60,14 @@ static const char fd2string[] = "This file should stay opened";
 void
 do_prepare (int argc, char *argv[])
 {
-   size_t name_len;
-
-   name_len = strlen (test_dir);
-   name1 = xmalloc (name_len + sizeof ("/execXXXXXX"));
-   mempcpy (mempcpy (name1, test_dir, name_len),
-	    "/execXXXXXX", sizeof ("/execXXXXXX"));
-   add_temp_file (name1);
-
-   name2 = xmalloc (name_len + sizeof ("/execXXXXXX"));
-   mempcpy (mempcpy (name2, test_dir, name_len),
-	    "/execXXXXXX", sizeof ("/execXXXXXX"));
-   add_temp_file (name2);
+  /* We must not open any files in the restart case.  */
+  if (restart)
+    return;
+
+  temp_fd1 = create_temp_file ("exec", &name1);
+  temp_fd2 = create_temp_file ("exec", &name2);
+  if (temp_fd1 < 0 || temp_fd2 < 0)
+    exit (1);
 }
 
 
@@ -120,8 +120,6 @@ int
 do_test (int argc, char *argv[])
 {
   pid_t pid;
-  int fd1;
-  int fd2;
   int flags;
   int status;
 
@@ -151,26 +149,18 @@ do_test (int argc, char *argv[])
   /* Prepare the test.  We are creating two files: one which file descriptor
      will be marked with FD_CLOEXEC, another which is not.  */
 
-   /* Open our test files.   */
-   fd1 = mkstemp (name1);
-   if (fd1 == -1)
-     error (EXIT_FAILURE, errno, "cannot open test file `%s'", name1);
-   fd2 = mkstemp (name2);
-   if (fd2 == -1)
-     error (EXIT_FAILURE, errno, "cannot open test file `%s'", name2);
-
    /* Set the bit.  */
-   flags = fcntl (fd1, F_GETFD, 0);
+   flags = fcntl (temp_fd1, F_GETFD, 0);
    if (flags < 0)
      error (EXIT_FAILURE, errno, "cannot get flags");
    flags |= FD_CLOEXEC;
-   if (fcntl (fd1, F_SETFD, flags) < 0)
+   if (fcntl (temp_fd1, F_SETFD, flags) < 0)
      error (EXIT_FAILURE, errno, "cannot set flags");
 
    /* Write something in the files.  */
-   if (write (fd1, fd1string, strlen (fd1string)) != strlen (fd1string))
+   if (write (temp_fd1, fd1string, strlen (fd1string)) != strlen (fd1string))
      error (EXIT_FAILURE, errno, "cannot write to first file");
-   if (write (fd2, fd2string, strlen (fd2string)) != strlen (fd2string))
+   if (write (temp_fd2, fd2string, strlen (fd2string)) != strlen (fd2string))
      error (EXIT_FAILURE, errno, "cannot write to second file");
 
   /* We want to test the `exec' function.  To do this we restart the program
@@ -181,8 +171,8 @@ do_test (int argc, char *argv[])
       char fd1name[18];
       char fd2name[18];
 
-      snprintf (fd1name, sizeof fd1name, "%d", fd1);
-      snprintf (fd2name, sizeof fd2name, "%d", fd2);
+      snprintf (fd1name, sizeof fd1name, "%d", temp_fd1);
+      snprintf (fd2name, sizeof fd2name, "%d", temp_fd2);
 
       /* This is the child.  Construct the command line.  */
       if (argc == 5)
@@ -205,9 +195,5 @@ do_test (int argc, char *argv[])
     error (EXIT_FAILURE, 0, "Child terminated incorrectly");
   status = WEXITSTATUS (status);
 
-  /* Remove the test files.  */
-  unlink (name1);
-  unlink (name2);
-
   return status;
 }
diff --git a/posix/tst-pathconf.c b/posix/tst-pathconf.c
index cce59e6d47..88df792ab3 100644
--- a/posix/tst-pathconf.c
+++ b/posix/tst-pathconf.c
@@ -162,11 +162,5 @@ out_nofifo:
       ret = 1;
     }
 
-  if (rmdir (dirbuf) != 0)
-    {
-      printf ("Could not remove directory (%s)\n", strerror (errno));
-      ret = 1;
-    }
-
   return ret;
 }
diff --git a/posix/tst-spawn.c b/posix/tst-spawn.c
index 2f960ba223..08d92bd7a7 100644
--- a/posix/tst-spawn.c
+++ b/posix/tst-spawn.c
@@ -50,6 +50,11 @@ static char *name1;
 static char *name2;
 static char *name3;
 
+/* Descriptors for the temporary files.  */
+static int temp_fd1 = -1;
+static int temp_fd2 = -1;
+static int temp_fd3 = -1;
+
 /* The contents of our files.  */
 static const char fd1string[] = "This file should get closed";
 static const char fd2string[] = "This file should stay opened";
@@ -60,23 +65,15 @@ static const char fd3string[] = "This file will be opened";
 void
 do_prepare (int argc, char *argv[])
 {
-   size_t name_len;
-
-   name_len = strlen (test_dir);
-   name1 = (char *) xmalloc (name_len + sizeof ("/spawnXXXXXX"));
-   mempcpy (mempcpy (name1, test_dir, name_len),
-	    "/spawnXXXXXX", sizeof ("/spawnXXXXXX"));
-   add_temp_file (name1);
-
-   name2 = (char *) xmalloc (name_len + sizeof ("/spawnXXXXXX"));
-   mempcpy (mempcpy (name2, test_dir, name_len),
-	    "/spawnXXXXXX", sizeof ("/spawnXXXXXX"));
-   add_temp_file (name2);
-
-   name3 = (char *) xmalloc (name_len + sizeof ("/spawnXXXXXX"));
-   mempcpy (mempcpy (name3, test_dir, name_len),
-	    "/spawnXXXXXX", sizeof ("/spawnXXXXXX"));
-   add_temp_file (name3);
+  /* We must not open any files in the restart case.  */
+  if (restart)
+    return;
+
+  temp_fd1 = create_temp_file ("spawn", &name1);
+  temp_fd2 = create_temp_file ("spawn", &name2);
+  temp_fd3 = create_temp_file ("spawn", &name3);
+  if (temp_fd1 < 0 || temp_fd2 < 0 || temp_fd3 < 0)
+    exit (1);
 }
 
 
@@ -158,9 +155,6 @@ int
 do_test (int argc, char *argv[])
 {
   pid_t pid;
-  int fd1;
-  int fd2;
-  int fd3;
   int fd4;
   int status;
   posix_spawn_file_actions_t actions;
@@ -194,53 +188,42 @@ do_test (int argc, char *argv[])
   /* Prepare the test.  We are creating two files: one which file descriptor
      will be marked with FD_CLOEXEC, another which is not.  */
 
-   /* Open our test files.   */
-   fd1 = mkstemp (name1);
-   if (fd1 == -1)
-     error (EXIT_FAILURE, errno, "cannot open test file `%s'", name1);
-   fd2 = mkstemp (name2);
-   if (fd2 == -1)
-     error (EXIT_FAILURE, errno, "cannot open test file `%s'", name2);
-   fd3 = mkstemp (name3);
-   if (fd3 == -1)
-     error (EXIT_FAILURE, errno, "cannot open test file `%s'", name3);
-
    /* Write something in the files.  */
-   if (write (fd1, fd1string, strlen (fd1string)) != strlen (fd1string))
+   if (write (temp_fd1, fd1string, strlen (fd1string)) != strlen (fd1string))
      error (EXIT_FAILURE, errno, "cannot write to first file");
-   if (write (fd2, fd2string, strlen (fd2string)) != strlen (fd2string))
+   if (write (temp_fd2, fd2string, strlen (fd2string)) != strlen (fd2string))
      error (EXIT_FAILURE, errno, "cannot write to second file");
-   if (write (fd3, fd3string, strlen (fd3string)) != strlen (fd3string))
+   if (write (temp_fd3, fd3string, strlen (fd3string)) != strlen (fd3string))
      error (EXIT_FAILURE, errno, "cannot write to third file");
 
    /* Close the third file.  It'll be opened by `spawn'.  */
-   close (fd3);
+   close (temp_fd3);
 
    /* Tell `spawn' what to do.  */
    if (posix_spawn_file_actions_init (&actions) != 0)
      error (EXIT_FAILURE, errno, "posix_spawn_file_actions_init");
-   /* Close `fd1'.  */
-   if (posix_spawn_file_actions_addclose (&actions, fd1) != 0)
+   /* Close `temp_fd1'.  */
+   if (posix_spawn_file_actions_addclose (&actions, temp_fd1) != 0)
      error (EXIT_FAILURE, errno, "posix_spawn_file_actions_addclose");
    /* We want to open the third file.  */
    name3_copy = strdup (name3);
    if (name3_copy == NULL)
      error (EXIT_FAILURE, errno, "strdup");
-   if (posix_spawn_file_actions_addopen (&actions, fd3, name3_copy,
+   if (posix_spawn_file_actions_addopen (&actions, temp_fd3, name3_copy,
 					 O_RDONLY, 0666) != 0)
      error (EXIT_FAILURE, errno, "posix_spawn_file_actions_addopen");
    /* Overwrite the name to check that a copy has been made.  */
    memset (name3_copy, 'X', strlen (name3_copy));
 
    /* We dup the second descriptor.  */
-   fd4 = MAX (2, MAX (fd1, MAX (fd2, fd3))) + 1;
-   if (posix_spawn_file_actions_adddup2 (&actions, fd2, fd4) != 0)
+   fd4 = MAX (2, MAX (temp_fd1, MAX (temp_fd2, temp_fd3))) + 1;
+   if (posix_spawn_file_actions_adddup2 (&actions, temp_fd2, fd4) != 0)
      error (EXIT_FAILURE, errno, "posix_spawn_file_actions_adddup2");
 
    /* Now spawn the process.  */
-   snprintf (fd1name, sizeof fd1name, "%d", fd1);
-   snprintf (fd2name, sizeof fd2name, "%d", fd2);
-   snprintf (fd3name, sizeof fd3name, "%d", fd3);
+   snprintf (fd1name, sizeof fd1name, "%d", temp_fd1);
+   snprintf (fd2name, sizeof fd2name, "%d", temp_fd2);
+   snprintf (fd3name, sizeof fd3name, "%d", temp_fd3);
    snprintf (fd4name, sizeof fd4name, "%d", fd4);
 
    for (i = 0; i < (argc == (restart ? 6 : 5) ? 4 : 1); i++)
@@ -274,10 +257,5 @@ do_test (int argc, char *argv[])
     error (EXIT_FAILURE, 0, "Child terminated incorrectly");
   status = WEXITSTATUS (status);
 
-  /* Remove the test files.  */
-  unlink (name1);
-  unlink (name2);
-  unlink (name3);
-
   return status;
 }
diff --git a/posix/tst-vfork3.c b/posix/tst-vfork3.c
index c104271c44..80898b3e41 100644
--- a/posix/tst-vfork3.c
+++ b/posix/tst-vfork3.c
@@ -159,11 +159,10 @@ do_prepare (void)
   strcpy (stpcpy (script1, tmpdirname), "/script1.sh");
   strcpy (stpcpy (script2, tmpdirname), "/script2.sh");
 
+  add_temp_file (tmpdirname);
   add_temp_file (script0);
   add_temp_file (script1);
   add_temp_file (script2);
-  /* Need to make sure tmpdirname is at the end of the linked list.  */
-  add_temp_file (tmpdirname);
 
   const char content0[] = "#!/bin/sh\necho empty\n";
   create_script (script0, content0, sizeof content0);