From: Roland McGrath <mcgrathr@google.com>
Date: Thu, 9 Jan 2014 18:13:10 +0000 (-0800)
Subject: Fix buffer underrun in i386-dis.c.
X-Git-Tag: gdb-7.7-release~52
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c8386be25767c8819fdfa9d24be6bb03ea004a78;p=thirdparty%2Fbinutils-gdb.git

Fix buffer underrun in i386-dis.c.

opcodes/
	* i386-dis.c (print_insn): Do not touch all_prefixes[-1] when
	last_rex_prefix is -1.

(cherry picked from commit e2e6193d65a20e6b7fccba288e5d1bc45b78d194)
---

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index fbb86a3d2a9..66e0365ade0 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,9 @@
+2014-01-09  Bradley Nelson  <bradnelson@google.com>
+	    Roland McGrath  <mcgrathr@google.com>
+
+	* i386-dis.c (print_insn): Do not touch all_prefixes[-1] when
+	last_rex_prefix is -1.
+
 2014-01-03  Maciej W. Rozycki  <macro@codesourcery.com>
 
 	* nds32-asm.c (parse_operand): Fix out-of-range integer constant.
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 2c28e52cc89..f2ec8c4947e 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -12645,7 +12645,7 @@ print_insn (bfd_vma pc, disassemble_info *info)
     }
 
   /* Check if the REX prefix is used.  */
-  if (rex_ignored == 0 && (rex ^ rex_used) == 0)
+  if (rex_ignored == 0 && (rex ^ rex_used) == 0 && last_rex_prefix >= 0)
     all_prefixes[last_rex_prefix] = 0;
 
   /* Check if the SEG prefix is used.  */