Carefully crafted invalid headers can cause buffer overrun.

[chaz/tar] / src / extract.c

diff --git a/src/extract.c b/src/extract.c
index 0e758a2c2456c4b50d526e67f017cfda850dd5ea..9be0a8b1392b95ae200192bdb131c86f0963f532 100644 (file)
--- a/src/extract.c
+++ b/src/extract.c
@@ -1,7 +1,7 @@
 /* Extract files from a tar archive.
 
    Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000,
-   2001, 2003, 2004 Free Software Foundation, Inc.
+   2001, 2003, 2004, 2005 Free Software Foundation, Inc.
 
    Written by John Gilmore, on 1985-11-19.
 
@@ -21,19 +21,10 @@
 
 #include <system.h>
 #include <quotearg.h>
+#include <utimens.h>
 #include <errno.h>
 #include <xgetcwd.h>
 
-#if HAVE_UTIME_H
-# include <utime.h>
-#else
-struct utimbuf
-  {
-    long actime;
-    long modtime;
-  };
-#endif
-
 #include "common.h"
 
 static bool we_are_root;       /* true if our effective uid == 0 */
@@ -201,15 +192,30 @@ set_mode (char const *file_name,
 
 /* Check time after successfully setting FILE_NAME's time stamp to T.  */
 static void
-check_time (char const *file_name, time_t t)
+check_time (char const *file_name, struct timespec t)
 {
-  time_t now;
-  if (t <= 0)
+  if (t.tv_sec <= 0)
     WARN ((0, 0, _("%s: implausibly old time stamp %s"),
-          file_name, tartime (t)));
-  else if (start_time < t && (now = time (0)) < t)
-    WARN ((0, 0, _("%s: time stamp %s is %lu s in the future"),
-          file_name, tartime (t), (unsigned long) (t - now)));
+          file_name, tartime (t, true)));
+  else if (timespec_lt (start_time, t))
+    {
+      struct timespec now;
+      gettime (&now);
+      if (timespec_lt (now, t))
+       {
+         unsigned long int ds = t.tv_sec - now.tv_sec;
+         int dns = t.tv_nsec - now.tv_nsec;
+         char dnsbuf[sizeof ".FFFFFFFFF"];
+         if (dns < 0)
+           {
+             dns += 1000000000;
+             ds--;
+           }
+         code_ns_fraction (dns, dnsbuf);
+         WARN ((0, 0, _("%s: time stamp %s is %lu%s s in the future"),
+                file_name, tartime (t, true), ds, dnsbuf));
+       }
+    }
 }
 
 /* Restore stat attributes (owner, group, mode and times) for
@@ -233,8 +239,6 @@ set_stat (char const *file_name,
          mode_t invert_permissions, enum permstatus permstatus,
          char typeflag)
 {
-  struct utimbuf utimbuf;
-
   if (typeflag != SYMTYPE)
     {
       /* We do the utime before the chmod because some versions of utime are
@@ -248,19 +252,16 @@ set_stat (char const *file_name,
 
          /* FIXME: incremental_option should set ctime too, but how?  */
 
-         if (incremental_option)
-           utimbuf.actime = stat_info->st_atime;
-         else
-           utimbuf.actime = start_time;
-
-         utimbuf.modtime = stat_info->st_mtime;
+         struct timespec ts[2];
+         ts[0] = incremental_option ? get_stat_atime (stat_info) : start_time;
+         ts[1] = get_stat_mtime (stat_info);
 
-         if (utime (file_name, &utimbuf) < 0)
+         if (utimens (file_name, ts) != 0)
            utime_error (file_name);
          else
            {
-             check_time (file_name, utimbuf.actime);
-             check_time (file_name, utimbuf.modtime);
+             check_time (file_name, ts[0]);
+             check_time (file_name, ts[1]);
            }
        }
 
@@ -778,7 +779,7 @@ extract_file (char *file_name, int typeflag)
 static int
 extract_link (char *file_name, int typeflag)
 {
-  char const *link_name = safer_name_suffix (current_stat_info.link_name, 
+  char const *link_name = safer_name_suffix (current_stat_info.link_name,
                                              true, absolute_names_option);
   int interdir_made = 0;
 
@@ -1134,7 +1135,7 @@ extract_archive (void)
   if (verbose_option)
     print_header (&current_stat_info, -1);
 
-  file_name = safer_name_suffix (current_stat_info.file_name, 
+  file_name = safer_name_suffix (current_stat_info.file_name,
                                  false, absolute_names_option);
   if (strip_name_components)
     {