glob: Add new test tst-glob-tilde

The new test checks for memory leaks (see bug 22325) and attempts
to trigger the buffer overflow in bug 22320.

1 files changed, 136 insertions, 0 deletions

diff --git a/posix/tst-glob-tilde.c b/posix/tst-glob-tilde.c
new file mode 100644
index 0000000000..9518b4a6f8
--- /dev/null
+++ b/posix/tst-glob-tilde.c
@@ -0,0 +1,136 @@
+/* Check for GLOB_TIDLE heap allocation issues (bug 22320, bug 22325).
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <glob.h>
+#include <mcheck.h>
+#include <nss.h>
+#include <pwd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <support/check.h>
+#include <support/support.h>
+
+/* Flag which indicates whether to pass the GLOB_ONLYDIR flag.  */
+static int do_onlydir;
+
+/* Flag which indicates whether to pass the GLOB_NOCHECK flag.  */
+static int do_nocheck;
+
+/* Flag which indicates whether to pass the GLOB_MARK flag.  */
+static int do_mark;
+
+static void
+one_test (const char *prefix, const char *middle, const char *suffix)
+{
+  char *pattern = xasprintf ("%s%s%s", prefix, middle, suffix);
+  int flags = GLOB_TILDE;
+  if (do_onlydir)
+    flags |= GLOB_ONLYDIR;
+  if (do_nocheck)
+    flags |= GLOB_NOCHECK;
+  if (do_mark)
+    flags |= GLOB_MARK;
+  glob_t gl;
+  /* This glob call might result in crashes or memory leaks.  */
+  if (glob (pattern, flags, NULL, &gl) == 0)
+    globfree (&gl);
+  free (pattern);
+}
+
+enum
+  {
+    /* The largest base being tested.  */
+    largest_base_size = 500000,
+
+    /* The actual size is the base size plus a variable whose absolute
+       value is not greater than this.  This helps malloc to trigger
+       overflows.  */
+    max_size_skew = 16,
+
+    /* The maximum string length supported by repeating_string
+       below.  */
+    repeat_size = largest_base_size + max_size_skew,
+  };
+
+/* Used to construct strings which repeat a single character 'x'.  */
+static char *repeat;
+
+/* Return a string of SIZE characters.  */
+const char *
+repeating_string (int size)
+{
+  TEST_VERIFY (size >= 0);
+  TEST_VERIFY (size <= repeat_size);
+  const char *repeated_shifted = repeat + repeat_size - size;
+  TEST_VERIFY (strlen (repeated_shifted) == size);
+  return repeated_shifted;
+}
+
+static int
+do_test (void)
+{
+  /* Avoid network-based NSS modules and initialize nss_files with a
+     dummy lookup.  This has to come before mtrace because NSS does
+     not free all memory.  */
+  __nss_configure_lookup ("passwd", "files");
+  (void) getpwnam ("root");
+
+  mtrace ();
+
+  repeat = xmalloc (repeat_size + 1);
+  memset (repeat, 'x', repeat_size);
+  repeat[repeat_size] = '\0';
+
+  /* These numbers control the size of the user name.  The values
+     cover the minimum (0), a typical size (8), a large
+     stack-allocated size (100000), and a somewhat large
+     heap-allocated size (largest_base_size).  */
+  static const int base_sizes[] = { 0, 8, 100, 100000, largest_base_size, -1 };
+
+  for (do_onlydir = 0; do_onlydir < 2; ++do_onlydir)
+    for (do_nocheck = 0; do_nocheck < 2; ++do_nocheck)
+      for (do_mark = 0; do_mark < 2; ++do_mark)
+        for (int base_idx = 0; base_sizes[base_idx] >= 0; ++base_idx)
+          {
+            for (int size_skew = -max_size_skew; size_skew <= max_size_skew;
+                 ++size_skew)
+              {
+                int size = base_sizes[base_idx] + size_skew;
+                if (size < 0)
+                  continue;
+
+                const char *user_name = repeating_string (size);
+                one_test ("~", user_name, "/a/b");
+              }
+
+            const char *user_name = repeating_string (base_sizes[base_idx]);
+            one_test ("~", user_name, "");
+            one_test ("~", user_name, "/");
+            one_test ("~", user_name, "/a");
+            one_test ("~", user_name, "/*/*");
+            one_test ("~", user_name, "\\/");
+            one_test ("/~", user_name, "");
+            one_test ("*/~", user_name, "/a/b");
+          }
+
+  free (repeat);
+
+  return 0;
+}
+
+#include <support/test-driver.c>