gdb/gdb-6.5-dwarf-stack-overflow.patch

for gdb/ChangeLog:
2006-08-22  Will Drewry <wad@google.com>
	    Tavis Ormandy <taviso@google.com>

	* dwarf2read.c (decode_locdesc): Enforce location description stack
	boundaries.
	* dwarfread.c (locval): Likewise.

Index: gdb-6.5/gdb/dwarf2read.c
===================================================================
--- gdb-6.5.orig/gdb/dwarf2read.c	2006-09-04 02:02:23.000000000 -0300
+++ gdb-6.5/gdb/dwarf2read.c	2006-09-04 02:02:23.000000000 -0300
@@ -8667,8 +8667,7 @@ dwarf2_fundamental_type (struct objfile 
    callers will only want a very basic result and this can become a
    complaint.
 
-   Note that stack[0] is unused except as a default error return.
-   Note that stack overflow is not yet handled.  */
+   Note that stack[0] is unused except as a default error return. */
 
 static CORE_ADDR
 decode_locdesc (struct dwarf_block *blk, struct dwarf2_cu *cu)
@@ -8685,7 +8684,7 @@ decode_locdesc (struct dwarf_block *blk,
 
   i = 0;
   stacki = 0;
-  stack[stacki] = 0;
+  stack[++stacki] = 0;
 
   while (i < size)
     {
@@ -8864,6 +8863,16 @@ decode_locdesc (struct dwarf_block *blk,
 		     dwarf_stack_op_name (op));
 	  return (stack[stacki]);
 	}
+      /* Enforce maximum stack depth of size-1 to avoid ++stacki writing
+         outside of the allocated space. Also enforce minimum > 0.
+         -- wad@google.com 14 Aug 2006 */
+      if (stacki >= sizeof (stack) / sizeof (*stack) - 1)
+	internal_error (__FILE__, __LINE__,
+	                _("location description stack too deep: %d"),
+	                stacki);
+      if (stacki <= 0)
+	internal_error (__FILE__, __LINE__,
+	                _("location description stack too shallow"));
     }
   return (stack[stacki]);
 }
Index: gdb-6.5/gdb/dwarfread.c
===================================================================
--- gdb-6.5.orig/gdb/dwarfread.c	2005-12-17 20:33:59.000000000 -0200
+++ gdb-6.5/gdb/dwarfread.c	2006-09-04 02:02:23.000000000 -0300
@@ -2138,9 +2138,7 @@ decode_line_numbers (char *linetable)
 
    NOTES
 
-   Note that stack[0] is unused except as a default error return.
-   Note that stack overflow is not yet handled.
- */
+   Note that stack[0] is unused except as a default error return. */
 
 static int
 locval (struct dieinfo *dip)
@@ -2160,7 +2158,7 @@ locval (struct dieinfo *dip)
   loc += nbytes;
   end = loc + locsize;
   stacki = 0;
-  stack[stacki] = 0;
+  stack[++stacki] = 0;
   dip->isreg = 0;
   dip->offreg = 0;
   dip->optimized_out = 1;
@@ -2224,6 +2222,16 @@ locval (struct dieinfo *dip)
 	  stacki--;
 	  break;
 	}
+      /* Enforce maximum stack depth of size-1 to avoid ++stacki writing
+         outside of the allocated space. Also enforce minimum > 0.
+         -- wad@google.com 14 Aug 2006 */
+      if (stacki >= sizeof (stack) / sizeof (*stack) - 1)
+	internal_error (__FILE__, __LINE__,
+	                _("location description stack too deep: %d"),
+	                stacki);
+      if (stacki <= 0)
+	internal_error (__FILE__, __LINE__,
+	                _("location description stack too shallow"));
     }
   return (stack[stacki]);
 }