[binutils-gdb] alpha-vms: Sanity check ETIR__C_CTL_DFLOC index

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=f75fbe8ad2e3d9b34bf1f448a6df328ff361822f

commit f75fbe8ad2e3d9b34bf1f448a6df328ff361822f
Author: Alan Modra <amodra@gmail.com>
Date:   Thu Mar 26 10:49:27 2020 +1030

    alpha-vms: Sanity check ETIR__C_CTL_DFLOC index
    
    I doubt anyone will want to create more than 16M debug location
    entries.  If there is no bound the object format allows for 32-bit
    indices and of course fuzzers find that and attempt allocation of up
    to a 16G byte array.  The patch also fixes potential integer overflows
    in calculating the array size.
    
            * vms-alpha.c (dst_define_location): Limit size of dst_ptr_offsets
            array.
            (_bfd_vms_slurp_object_records): Rename "err" to "ok".

Diff:
---
 bfd/ChangeLog   |  6 ++++++
 bfd/vms-alpha.c | 26 +++++++++++++++++---------
 2 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index cac27e37ec9..b5a2e7d447d 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2020-03-26  Alan Modra  <amodra@gmail.com>
+
+	* vms-alpha.c (dst_define_location): Limit size of dst_ptr_offsets
+	array.
+	(_bfd_vms_slurp_object_records): Rename "err" to "ok".
+
 2020-03-25  Nick Clifton  <nickc@redhat.com>
 
 	* cofflink.c (bfd_coff_get_internal_extra_pe_aouthdr): New
diff --git a/bfd/vms-alpha.c b/bfd/vms-alpha.c
index c08d35d4b2e..594363b32af 100644
--- a/bfd/vms-alpha.c
+++ b/bfd/vms-alpha.c
@@ -1553,6 +1553,14 @@ dst_define_location (bfd *abfd, unsigned int loc)
 {
   vms_debug2 ((4, "dst_define_location (%d)\n", (int)loc));
 
+  if (loc > 1 << 24)
+    {
+      /* 16M entries ought to be plenty.  */
+      bfd_set_error (bfd_error_bad_value);
+      _bfd_error_handler (_("dst_define_location %u too large"), loc);
+      return FALSE;
+    }
+
   /* Grow the ptr offset table if necessary.  */
   if (loc + 1 > PRIV (dst_ptr_offsets_count))
     {
@@ -2634,7 +2642,7 @@ _bfd_vms_slurp_eeom (bfd *abfd)
 static bfd_boolean
 _bfd_vms_slurp_object_records (bfd * abfd)
 {
-  bfd_boolean err;
+  bfd_boolean ok;
   int type;
 
   do
@@ -2651,27 +2659,27 @@ _bfd_vms_slurp_object_records (bfd * abfd)
       switch (type)
 	{
 	case EOBJ__C_EMH:
-	  err = _bfd_vms_slurp_ehdr (abfd);
+	  ok = _bfd_vms_slurp_ehdr (abfd);
 	  break;
 	case EOBJ__C_EEOM:
-	  err = _bfd_vms_slurp_eeom (abfd);
+	  ok = _bfd_vms_slurp_eeom (abfd);
 	  break;
 	case EOBJ__C_EGSD:
-	  err = _bfd_vms_slurp_egsd (abfd);
+	  ok = _bfd_vms_slurp_egsd (abfd);
 	  break;
 	case EOBJ__C_ETIR:
-	  err = TRUE; /* _bfd_vms_slurp_etir (abfd); */
+	  ok = TRUE; /* _bfd_vms_slurp_etir (abfd); */
 	  break;
 	case EOBJ__C_EDBG:
-	  err = _bfd_vms_slurp_edbg (abfd);
+	  ok = _bfd_vms_slurp_edbg (abfd);
 	  break;
 	case EOBJ__C_ETBT:
-	  err = _bfd_vms_slurp_etbt (abfd);
+	  ok = _bfd_vms_slurp_etbt (abfd);
 	  break;
 	default:
-	  err = FALSE;
+	  ok = FALSE;
 	}
-      if (!err)
+      if (!ok)
 	{
 	  vms_debug2 ((2, "slurp type %d failed\n", type));
 	  return FALSE;