[PATCH] bfd robustification (avoid crashes on bogus ar archives)

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[PATCH] bfd robustification (avoid crashes on bogus ar archives)

Jakub Jelinek
Hi!

Following patch robustifies extended names archive handling.
Ok to commit?

2005-06-21  Jakub Jelinek  <[hidden email]>

        * libbfd-in.h (struct artdata): Add extended_names_size field.
        * libbfd.h: Rebuilt.
        * coff-rs600.c (_bfd_xcoff_archive_p): Don't clear fields in freshly
        allocated object by bfd_zalloc.
        * coff64-rs6000.c (xcoff64_archive_p): Likewise.
        * ecoff.c (_bfd_ecoff_archive_p): Likewise.
        * archive.c (_bfd_generic_mkarchive, bfd_generic_archive_p): Likewise.
        (get_extended_arelt_filename): Fail if index is bigger or equal to
        extended_names_size.
        (_bfd_generic_read_ar_hdr_mag): Don't set bfd_error_malformed_archive,
        get_extended_arelt_filename already did that.
        (_bfd_slurp_extended_name_table): Initialize extended_names_size field.
        Allocate one extra byte and clear it, in case extended names table
        is not terminated.

--- bfd/libbfd-in.h.jj 2005-06-20 12:16:18.000000000 +0200
+++ bfd/libbfd-in.h 2005-06-21 18:45:56.000000000 +0200
@@ -64,6 +64,7 @@ struct artdata {
   carsym *symdefs; /* the symdef entries */
   symindex symdef_count; /* how many there are */
   char *extended_names; /* clever intel extension */
+  bfd_size_type extended_names_size; /* Size of extended names */
   /* when more compilers are standard C, this can be a time_t */
   long  armap_timestamp; /* Timestamp value written into armap.
    This is used for BSD archives to check
--- bfd/libbfd.h.jj 2005-06-20 12:16:18.000000000 +0200
+++ bfd/libbfd.h 2005-06-21 18:46:32.000000000 +0200
@@ -69,6 +69,7 @@ struct artdata {
   carsym *symdefs; /* the symdef entries */
   symindex symdef_count; /* how many there are */
   char *extended_names; /* clever intel extension */
+  bfd_size_type extended_names_size; /* Size of extended names */
   /* when more compilers are standard C, this can be a time_t */
   long  armap_timestamp; /* Timestamp value written into armap.
    This is used for BSD archives to check
--- bfd/coff64-rs6000.c.jj 2005-06-09 10:58:49.000000000 +0200
+++ bfd/coff64-rs6000.c 2005-06-21 18:59:07.000000000 +0200
@@ -1983,10 +1983,12 @@ xcoff64_archive_p (abfd)
   if (bfd_ardata (abfd) == (struct artdata *) NULL)
     goto error_ret_restore;
 
-  bfd_ardata (abfd)->cache = NULL;
-  bfd_ardata (abfd)->archive_head = NULL;
-  bfd_ardata (abfd)->symdefs = NULL;
-  bfd_ardata (abfd)->extended_names = NULL;
+  /* Already cleared by bfd_zalloc above.
+     bfd_ardata (abfd)->cache = NULL;
+     bfd_ardata (abfd)->archive_head = NULL;
+     bfd_ardata (abfd)->symdefs = NULL;
+     bfd_ardata (abfd)->extended_names = NULL;
+     bfd_ardata (abfd)->extended_names_size = 0;  */
   bfd_ardata (abfd)->first_file_filepos = bfd_scan_vma (hdr.firstmemoff,
  (const char **) NULL,
  10);
--- bfd/coff-rs6000.c.jj 2005-06-09 10:58:49.000000000 +0200
+++ bfd/coff-rs6000.c 2005-06-21 18:56:11.000000000 +0200
@@ -1294,10 +1294,12 @@ _bfd_xcoff_archive_p (abfd)
   if (bfd_ardata (abfd) == (struct artdata *) NULL)
     goto error_ret_restore;
 
-  bfd_ardata (abfd)->cache = NULL;
-  bfd_ardata (abfd)->archive_head = NULL;
-  bfd_ardata (abfd)->symdefs = NULL;
-  bfd_ardata (abfd)->extended_names = NULL;
+  /* Cleared by bfd_zalloc above.
+     bfd_ardata (abfd)->cache = NULL;
+     bfd_ardata (abfd)->archive_head = NULL;
+     bfd_ardata (abfd)->symdefs = NULL;
+     bfd_ardata (abfd)->extended_names = NULL;
+     bfd_ardata (abfd)->extended_names_size = 0;  */
 
   /* Now handle the two formats.  */
   if (magic[1] != 'b')
--- bfd/ecoff.c.jj 2005-05-13 23:44:07.000000000 +0200
+++ bfd/ecoff.c 2005-06-21 18:59:49.000000000 +0200
@@ -3182,11 +3182,13 @@ _bfd_ecoff_archive_p (bfd *abfd)
     }
 
   bfd_ardata (abfd)->first_file_filepos = SARMAG;
-  bfd_ardata (abfd)->cache = NULL;
-  bfd_ardata (abfd)->archive_head = NULL;
-  bfd_ardata (abfd)->symdefs = NULL;
-  bfd_ardata (abfd)->extended_names = NULL;
-  bfd_ardata (abfd)->tdata = NULL;
+  /* Already cleared by bfd_zalloc above.
+     bfd_ardata (abfd)->cache = NULL;
+     bfd_ardata (abfd)->archive_head = NULL;
+     bfd_ardata (abfd)->symdefs = NULL;
+     bfd_ardata (abfd)->extended_names = NULL;
+     bfd_ardata (abfd)->extended_names_size = 0;
+     bfd_ardata (abfd)->tdata = NULL;  */
 
   if (! _bfd_ecoff_slurp_armap (abfd)
       || ! _bfd_ecoff_slurp_extended_name_table (abfd))
--- bfd/archive.c.jj 2005-06-17 15:22:56.000000000 +0200
+++ bfd/archive.c 2005-06-21 19:03:51.000000000 +0200
@@ -182,11 +182,13 @@ _bfd_generic_mkarchive (bfd *abfd)
   if (bfd_ardata (abfd) == NULL)
     return FALSE;
 
-  bfd_ardata (abfd)->cache = NULL;
-  bfd_ardata (abfd)->archive_head = NULL;
-  bfd_ardata (abfd)->symdefs = NULL;
-  bfd_ardata (abfd)->extended_names = NULL;
-  bfd_ardata (abfd)->tdata = NULL;
+  /* Already cleared by bfd_zalloc above.
+     bfd_ardata (abfd)->cache = NULL;
+     bfd_ardata (abfd)->archive_head = NULL;
+     bfd_ardata (abfd)->symdefs = NULL;
+     bfd_ardata (abfd)->extended_names = NULL;
+     bfd_ardata (abfd)->extended_names_size = 0;
+     bfd_ardata (abfd)->tdata = NULL;  */
 
   return TRUE;
 }
@@ -335,7 +337,7 @@ get_extended_arelt_filename (bfd *arch,
   errno = 0;
   /* Skip first char, which is '/' in SVR4 or ' ' in some other variants.  */
   index = strtol (name + 1, NULL, 10);
-  if (errno != 0)
+  if (errno != 0 || index >= bfd_ardata (arch)->extended_names_size)
     {
       bfd_set_error (bfd_error_malformed_archive);
       return NULL;
@@ -405,10 +407,7 @@ _bfd_generic_read_ar_hdr_mag (bfd *abfd,
     {
       filename = get_extended_arelt_filename (abfd, hdr.ar_name);
       if (filename == NULL)
- {
-  bfd_set_error (bfd_error_malformed_archive);
-  return NULL;
- }
+ return NULL;
     }
   /* BSD4.4-style long filename.
      Only implemented for reading, so far!  */
@@ -629,11 +628,13 @@ bfd_generic_archive_p (bfd *abfd)
     }
 
   bfd_ardata (abfd)->first_file_filepos = SARMAG;
-  bfd_ardata (abfd)->cache = NULL;
-  bfd_ardata (abfd)->archive_head = NULL;
-  bfd_ardata (abfd)->symdefs = NULL;
-  bfd_ardata (abfd)->extended_names = NULL;
-  bfd_ardata (abfd)->tdata = NULL;
+  /* Cleared by bfd_zalloc above.
+     bfd_ardata (abfd)->cache = NULL;
+     bfd_ardata (abfd)->archive_head = NULL;
+     bfd_ardata (abfd)->symdefs = NULL;
+     bfd_ardata (abfd)->extended_names = NULL;
+     bfd_ardata (abfd)->extended_names_size = 0;
+     bfd_ardata (abfd)->tdata = NULL;  */
 
   if (!BFD_SEND (abfd, _bfd_slurp_armap, (abfd))
       || !BFD_SEND (abfd, _bfd_slurp_extended_name_table, (abfd)))
@@ -1067,6 +1068,7 @@ _bfd_slurp_extended_name_table (bfd *abf
   strncmp (nextname, "//              ", 16) != 0)
  {
   bfd_ardata (abfd)->extended_names = NULL;
+  bfd_ardata (abfd)->extended_names_size = 0;
   return TRUE;
  }
 
@@ -1075,7 +1077,11 @@ _bfd_slurp_extended_name_table (bfd *abf
  return FALSE;
 
       amt = namedata->parsed_size;
-      bfd_ardata (abfd)->extended_names = bfd_zalloc (abfd, amt);
+      if (amt + 1 == 0)
+        goto byebye;
+
+      bfd_ardata (abfd)->extended_names_size = amt;
+      bfd_ardata (abfd)->extended_names = bfd_zalloc (abfd, amt + 1);
       if (bfd_ardata (abfd)->extended_names == NULL)
  {
  byebye:
@@ -1098,15 +1104,17 @@ _bfd_slurp_extended_name_table (bfd *abf
  trailing '/'.  DOS/NT created archive often have \ in them
  We'll fix all problems here..  */
       {
- char *temp = bfd_ardata (abfd)->extended_names;
+        char *ext_names = bfd_ardata (abfd)->extended_names;
+ char *temp = ext_names;
  char *limit = temp + namedata->parsed_size;
  for (; temp < limit; ++temp)
   {
     if (*temp == '\012')
-      temp[temp[-1] == '/' ? -1 : 0] = '\0';
+      temp[temp > ext_names && temp[-1] == '/' ? -1 : 0] = '\0';
     if (*temp == '\\')
       *temp = '/';
   }
+ *limit = '\0';
       }
 
       /* Pad to an even boundary if you have to.  */

        Jakub