Fix a buffer overflow, caused by improper bounds checking of the

PAX extended headers.  By tricking a user into processing a specially
crafted tar archive, this could be exploited to execute arbitrary
code with the privileges of the user.

Security:	CVE-2006-0300
Approved by:	portmgr (erwin)
Obtained from:	Ubuntu

2 files changed, 125 insertions, 1 deletions

diff --git a/archivers/gtar/Makefile b/archivers/gtar/Makefile
index c51a701ad201..f40aaf7b4c05 100644
--- a/archivers/gtar/Makefile
+++ b/archivers/gtar/Makefile
@@ -7,7 +7,7 @@
 
 PORTNAME=	tar
 PORTVERSION=	1.15.1
-PORTREVISION=	1
+PORTREVISION=	2
 CATEGORIES=	archivers sysutils
 MASTER_SITES=	${MASTER_SITE_GNU}
 MASTER_SITE_SUBDIR=	${PORTNAME}
diff --git a/archivers/gtar/files/patch-src_xheader.c b/archivers/gtar/files/patch-src_xheader.c
new file mode 100644
index 000000000000..c64261b50cb8
--- /dev/null
+++ b/archivers/gtar/files/patch-src_xheader.c
@@ -0,0 +1,124 @@
+
+$FreeBSD$
+
+--- src/xheader.c.orig
++++ src/xheader.c
+@@ -783,6 +783,32 @@
+   xheader_print (xhdr, keyword, sbuf);
+ }
+ 
++static bool
++decode_num (uintmax_t *num, char const *arg, uintmax_t maxval,
++        char const *keyword)
++{
++  uintmax_t u;
++  char *arg_lim;
++
++  if (! (ISDIGIT (*arg)
++     && (errno = 0, u = strtoumax (arg, &arg_lim, 10), !*arg_lim)))
++    {
++      ERROR ((0, 0, _("Malformed extended header: invalid %s=%s"),
++          keyword, arg));
++      return false;
++    }
++
++  if (! (u <= maxval && errno != ERANGE))
++    {
++      ERROR ((0, 0, _("Extended header %s=%s is out of range"),
++        keyword, arg));
++      return false;
++    }
++
++  *num = u;
++  return true;
++}
++
+ static void
+ dummy_coder (struct tar_stat_info const *st __attribute__ ((unused)),
+ 	     char const *keyword __attribute__ ((unused)),
+@@ -821,7 +847,7 @@
+ gid_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, TYPE_MAXIMUM (gid_t), "gid"))
+     st->stat.st_gid = u;
+ }
+ 
+@@ -903,7 +929,7 @@
+ size_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), "size"))
+     st->archive_file_size = st->stat.st_size = u;
+ }
+ 
+@@ -918,7 +944,7 @@
+ uid_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, TYPE_MAXIMUM (uid_t), "uid"))
+     st->stat.st_uid = u;
+ }
+ 
+@@ -946,7 +972,7 @@
+ sparse_size_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), "GNU.sparse.size"))
+     st->stat.st_size = u;
+ }
+ 
+@@ -962,10 +988,10 @@
+ sparse_numblocks_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, SIZE_MAX, "GNU.sparse.numblocks"))
+     {
+       st->sparse_map_size = u;
+-      st->sparse_map = calloc(st->sparse_map_size, sizeof(st->sparse_map[0]));
++      st->sparse_map = xcalloc (u, sizeof st->sparse_map[0]);
+       st->sparse_map_avail = 0;
+     }
+ }
+@@ -982,8 +1008,14 @@
+ sparse_offset_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, TYPE_MAXIMUM (off_t), "GNU.sparse.offset"))
++    {
++      if (st->sparse_map_avail < st->sparse_map_size)
+     st->sparse_map[st->sparse_map_avail].offset = u;
++      else
++    ERROR ((0, 0, _("Malformed extended header: excess %s=%s"),
++        "GNU.sparse.offset", arg));
++    }
+ }
+ 
+ static void
+@@ -998,15 +1030,13 @@
+ sparse_numbytes_decoder (struct tar_stat_info *st, char const *arg)
+ {
+   uintmax_t u;
+-  if (xstrtoumax (arg, NULL, 10, &u, "") == LONGINT_OK)
++  if (decode_num (&u, arg, SIZE_MAX, "GNU.sparse.numbytes"))
+     {
+       if (st->sparse_map_avail == st->sparse_map_size)
+-	{
+-	  st->sparse_map_size *= 2;
+-	  st->sparse_map = xrealloc (st->sparse_map,
+-				     st->sparse_map_size
+-				     * sizeof st->sparse_map[0]);
+-	}
++        st->sparse_map = x2nrealloc (st->sparse_map,
++                                    &st->sparse_map_size,
++                                    sizeof st->sparse_map[0]);
++
+       st->sparse_map[st->sparse_map_avail++].numbytes = u;
+     }
+ }