commit c3a6a9dfc "libdw: Use signedness of subrange type to
determine array bounds" introduced a type check on a DIE which
exposed a latent bug in the get_type function. Even if the type
of a DIE couldn't be determined it would call dwarf_peel_type
on it. The gcc undefined sanitizer would flag this as being
undefined behaviour because the second argument of the function
is marked as non-NULL. Fix this by checking we actually have
a non-NULL type DIE.
Signed-off-by: Mark Wielaard <m...@klomp.org>
---
libdw/ChangeLog | 5 +++++
libdw/dwarf_aggregate_size.c | 2 +-
2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/libdw/ChangeLog b/libdw/ChangeLog
index 4275b830..311f34b5 100644
--- a/libdw/ChangeLog
+++ b/libdw/ChangeLog
@@ -1,3 +1,8 @@
+2021-10-18 Mark Wielaard <m...@klomp.org>
+
+ * dwarf_aggregate_size.c (get_type): Don't pass NULL to
+ dwarf_peel_type.
+
2021-10-06 Mark Wielaard <m...@klomp.org>
* dwarf_aggregate_size.c (array_size): Check signedness of child DIE
diff --git a/libdw/dwarf_aggregate_size.c b/libdw/dwarf_aggregate_size.c
index 96023d69..89f2029e 100644
--- a/libdw/dwarf_aggregate_size.c
+++ b/libdw/dwarf_aggregate_size.c
@@ -40,7 +40,7 @@ get_type (Dwarf_Die *die, Dwarf_Attribute *attr_mem,
Dwarf_Die *type_mem)
Dwarf_Die *type = INTUSE(dwarf_formref_die)
(INTUSE(dwarf_attr_integrate) (die, DW_AT_type, attr_mem), type_mem);
- if (INTUSE(dwarf_peel_type) (type, type) != 0)
+ if (type == NULL || INTUSE(dwarf_peel_type) (type, type) != 0)
return NULL;
return type;
--
2.18.4
