Make time zone file parser more robust [BZ #17715]

1 files changed, 200 insertions, 0 deletions

diff --git a/timezone/tst-tzset.c b/timezone/tst-tzset.c
new file mode 100644
index 0000000..aefcc76
--- /dev/null
+++ b/timezone/tst-tzset.c
@@ -0,0 +1,200 @@
+/* tzset tests with crafted time zone data.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+
+   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/>.  */
+
+#define _GNU_SOURCE 1
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/resource.h>
+#include <time.h>
+#include <unistd.h>
+
+static int do_test (void);
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
+
+/* Returns the name of a large TZ file.  */
+static char *
+create_tz_file (off64_t size)
+{
+  char *path;
+  int fd = create_temp_file ("tst-tzset-", &path);
+  if (fd < 0)
+    exit (1);
+
+  // Reopen for large-file support.
+  close (fd);
+  fd = open64 (path, O_WRONLY);
+  if (fd < 0)
+    {
+      printf ("open64 (%s) failed: %m\n", path);
+      exit (1);
+    }
+
+  static const char data[] = {
+    0x54, 0x5a, 0x69, 0x66, 0x32, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+    0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+    0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x58, 0x54, 0x47, 0x00, 0x00, 0x00,
+    0x54, 0x5a, 0x69, 0x66, 0x32, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+    0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
+    0x00, 0x00, 0x00, 0x04, 0xf8, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x58, 0x54, 0x47, 0x00, 0x00,
+    0x00, 0x0a, 0x58, 0x54, 0x47, 0x30, 0x0a
+  };
+  ssize_t ret = write (fd, data, sizeof (data));
+  if (ret < 0)
+    {
+      printf ("write failed: %m\n");
+      exit (1);
+    }
+  if ((size_t) ret != sizeof (data))
+    {
+      printf ("Short write\n");
+      exit (1);
+    }
+  if (lseek64 (fd, size, SEEK_CUR) < 0)
+    {
+      printf ("lseek failed: %m\n");
+      close (fd);
+      return NULL;
+    }
+  if (write (fd, "", 1) != 1)
+    {
+      printf ("Single-byte write failed\n");
+      close (fd);
+      return NULL;
+    }
+  if (close (fd) != 0)
+    {
+      printf ("close failed: %m\n");
+      exit (1);
+    }
+  return path;
+}
+
+static void
+test_tz_file (off64_t size)
+{
+  char *path = create_tz_file (size);
+  if (setenv ("TZ", path, 1) < 0)
+    {
+      printf ("setenv failed: %m\n");
+      exit (1);
+    }
+  tzset ();
+  free (path);
+}
+
+static int
+do_test (void)
+{
+  /* Limit the size of the process.  Otherwise, some of the tests will
+     consume a lot of resources.  */
+  {
+    struct rlimit limit;
+    if (getrlimit (RLIMIT_AS, &limit) != 0)
+      {
+	printf ("getrlimit (RLIMIT_AS) failed: %m\n");
+	return 1;
+      }
+    long target = 512 * 1024 * 1024;
+    if (limit.rlim_cur == RLIM_INFINITY || limit.rlim_cur > target)
+      {
+	limit.rlim_cur = 512 * 1024 * 1024;
+	if (setrlimit (RLIMIT_AS, &limit) != 0)
+	  {
+	    printf ("setrlimit (RLIMIT_AS) failed: %m\n");
+	    return 1;
+	  }
+      }
+  }
+
+  int errors = 0;
+  for (int i = 1; i <= 4; ++i)
+    {
+      char tz[16];
+      snprintf (tz, sizeof (tz), "XT%d", i);
+      if (setenv ("TZ", tz, 1) < 0)
+	{
+	  printf ("setenv failed: %m\n");
+	  return 1;
+	}
+      tzset ();
+      if (strcmp (tzname[0], tz) == 0)
+	{
+	  printf ("Unexpected success for %s\n", tz);
+	  ++errors;
+	}
+    }
+
+  /* Large TZ files.  */
+
+  /* This will succeed on 64-bit architectures, and fail on 32-bit
+     architectures.  It used to crash on 32-bit.  */
+  test_tz_file (64 * 1024 * 1024);
+
+  /* This will fail on 64-bit and 32-bit architectures.  It used to
+     cause a test timeout on 64-bit and crash on 32-bit if the TZ file
+     open succeeded for some reason (it does not use O_LARGEFILE in
+     regular builds).  */
+  test_tz_file (4LL * 1024 * 1024 * 1024 - 6);
+
+  /* Large TZ variables.  */
+  {
+    size_t length = 64 * 1024 * 1024;
+    char *value = malloc (length + 1);
+    if (value == NULL)
+      {
+	puts ("malloc failed: %m");
+	return 1;
+      }
+    value[length] = '\0';
+
+    memset (value, ' ', length);
+    value[0] = 'U';
+    value[1] = 'T';
+    value[2] = 'C';
+    if (setenv ("TZ", value, 1) < 0)
+      {
+	printf ("setenv failed: %m\n");
+	return 1;
+      }
+    tzset ();
+
+    memset (value, '0', length);
+    value[0] = '<';
+    value[length - 1] = '>';
+    if (setenv ("TZ", value, 1) < 0)
+      {
+	printf ("setenv failed: %m\n");
+	return 1;
+      }
+    tzset ();
+  }
+
+  return errors > 0;
+}