[COMMITTED] libdw: Correct data end checkfor deref_type operand in dwarf_getlocation

[COMMITTED] libdw: Correct data end checkfor deref_type operand in dwarf_getlocation

[Mark Wielaard]

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>
---

This wrong check caused the recent buildbot failure on some arches.

 libdw/ChangeLog           | 5 +++++
 libdw/dwarf_getlocation.c | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index ddf14e55..e0cd8f21 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 66eab3e9..553fdc98 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);
-- 
2.31.1