From: Mark Wielaard <mark@klomp.org>
Date: Tue, 14 Feb 2023 19:24:30 +0000 (+0100)
Subject: libdw: Correct data end checkfor deref_type operand in dwarf_getlocation
X-Git-Tag: elfutils-0.189~15
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0e8306768a6d0195c01644e7c5a6fff027fd19f2;p=thirdparty%2Felfutils.git

libdw: Correct data end checkfor deref_type operand in dwarf_getlocation

In __libdw_intern_expression we checked for one byte too many.
We only need one byte for the size and (at least one) for the uleb128
DIE reference.

Signed-off-by: Mark Wielaard <mark@klomp.org>
---

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index ddf14e550..e0cd8f212 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2023-02-14  Mark Wielaard  <mark@klomp.org>
+
+	* dwarf_getlocation.c (__libdw_intern_expression): Correct check
+	for deref_type.
+
 2023-02-10  Mark Wielaard  <mark@klomp.org>
 
 	* dwarf_getlocation.c (__libdw_intern_expression): Handle
diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c
index 66eab3e99..553fdc986 100644
--- a/libdw/dwarf_getlocation.c
+++ b/libdw/dwarf_getlocation.c
@@ -546,7 +546,7 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order,
 	case DW_OP_deref_type:
 	case DW_OP_GNU_deref_type:
 	case DW_OP_xderef_type:
-	  if (unlikely (data + 2 >= end_data))
+	  if (unlikely (data + 1 >= end_data))
 	    goto invalid;
 	  newloc->number = *data++;
 	  get_uleb128 (newloc->number2, data, end_data);