Prevent an illegal memory access in gprof by ensuring that string tables for aout...

	PR 23056
	* aoutx.h (aout_get_external_symbols): Allocate an extra byte at
	the end of the string table, and zero it.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 7cc35f36e5824d7d2939ec1a825ccc375cc4115f..e8b748b5bf1b53e691712f3b5adf48bea2921727 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2018-04-23  Nick Clifton  <nickc@redhat.com>
+
+       PR 23056
+       * aoutx.h (aout_get_external_symbols): Allocate an extra byte at
+       the end of the string table, and zero it.
+
 2018-04-23  Alan Modra  <amodra@gmail.com>
 
        * elf-linux-core.h (swap_linux_prpsinfo32_ugid32_out): Disable
@@ -7,6 +13,12 @@
        (swap_linux_prpsinfo64_ugid16_out): Likewise.
        * elf.c (elfcore_write_prpsinfo): Likewise.
 
+2018-04-23  Nick Clifton  <nickc@redhat.com>
+
+       PR 23056
+       * aoutx.h (aout_get_external_symbols): Allocate an extra byte at
+       the end of the string table, and zero it.
+
 2018-04-20  Alan Modra  <amodra@gmail.com>
 
        PR 22978

diff --git a/bfd/aoutx.h b/bfd/aoutx.h
index 7cc95614ee2fe6a835cf3255a3d4bcff35cc9819..023843b0be42fa6ec4ade4f3a4111f437776fc63 100644 (file)
--- a/bfd/aoutx.h
+++ b/bfd/aoutx.h
@@ -1343,7 +1343,7 @@ aout_get_external_symbols (bfd *abfd)
 #ifdef USE_MMAP
       if (stringsize >= BYTES_IN_WORD)
        {
-         if (! bfd_get_file_window (abfd, obj_str_filepos (abfd), stringsize,
+         if (! bfd_get_file_window (abfd, obj_str_filepos (abfd), stringsize + 1,
                                     &obj_aout_string_window (abfd), TRUE))
            return FALSE;
          strings = (char *) obj_aout_string_window (abfd).data;
@@ -1351,7 +1351,7 @@ aout_get_external_symbols (bfd *abfd)
       else
 #endif
        {
-         strings = (char *) bfd_malloc (stringsize);
+         strings = (char *) bfd_malloc (stringsize + 1);
          if (strings == NULL)
            return FALSE;
 
@@ -1370,7 +1370,8 @@ aout_get_external_symbols (bfd *abfd)
       /* Ensure that a zero index yields an empty string.  */
       strings[0] = '\0';
 
-      strings[stringsize - 1] = 0;
+      /* Ensure that the string buffer is NUL terminated.  */
+      strings[stringsize] = 0;
 
       obj_aout_external_strings (abfd) = strings;
       obj_aout_external_string_size (abfd) = stringsize;