https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64741
Bug ID: 64741
Summary: Incorrect size of UBSan type descriptors
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: sanitizer
Assignee: unassigned at gcc dot gnu.org
Reporter: y.gribov at samsung dot com
CC: dodji at gcc dot gnu.org, dvyukov at gcc dot gnu.org,
jakub at gcc dot gnu.org, kcc at gcc dot gnu.org,
ryabinin.a.a at gmail dot com
Created attachment 34540
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34540&action=edit
Proposed patch
UBSan uses incomplete type for all UBSan type descriptors:
struct {
short __typekind;
short __typeinfo;
char __typename[];
};
and this causes DECL_SIZE to return invalid (too short) values for generated
globals. This later causes ASan to report invalid (again, too short) size to
__asan_register_globals when UBSan is enabled together with ASan.
This may not be a problem for userspace (because only libubsan accesses these
descriptors and it's not sanitized) but causes false positives for kernel
(https://lkml.org/lkml/2015/1/22/670).
I attach a silly fix - if it looks more or less fine, I'll do the regtesting
and fw to gcc-patches.
