[LTP] [PATCH v2 0/3] safe_macros: Fix undefined behaviour in vararg handling

[Tudor Cretu]

Accessing elements in an empty va_list results in undefined behaviour[0]
that can include accessing arbitrary stack memory. While typically this
doesn't raise a fault, some new more security-oriented architectures
(e.g. CHERI[1] or Morello[2]) don't allow it.

Therefore, remove the variadicness from safe_* wrappers that always call
the functions with the optional argument included.

Adapt the respective SAFE_* macros to handle the change by passing a
default argument if they're omitted.

[0]: [ISO/IEC 9899:2011] Programming Languages—C, 3rd ed, paragraph 7.16.1.1
[1]: https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/
[2]: https://www.morello-project.org/

v2..v1:
  - PATCH 1: Remove the NULL argument for mode from SAFE_OPEN instances
    to avoid the pointer to int conversion.

Tudor Cretu (3):
  safe_open: Fix undefined behaviour in vararg handling
  safe_openat: Fix undefined behaviour in vararg handling
  safe_semctl: Fix undefined behaviour in vararg handling

 include/old/safe_macros.h                         |  6 ++++--
 include/safe_macros_fn.h                          |  3 ++-
 include/tst_safe_file_at.h                        | 10 ++++++----
 include/tst_safe_macros.h                         |  6 ++++--
 include/tst_safe_sysv_ipc.h                       | 14 +++++++++-----
 lib/safe_macros.c                                 | 13 +------------
 lib/tst_cgroup.c                                  |  2 +-
 lib/tst_safe_file_at.c                            | 11 +++--------
 lib/tst_safe_sysv_ipc.c                           | 10 +---------
 testcases/kernel/syscalls/fgetxattr/fgetxattr01.c |  2 +-
 testcases/kernel/syscalls/fgetxattr/fgetxattr02.c |  2 +-
 testcases/kernel/syscalls/fgetxattr/fgetxattr03.c |  2 +-
 testcases/kernel/syscalls/fsetxattr/fsetxattr01.c |  2 +-
 testcases/kernel/syscalls/fsetxattr/fsetxattr02.c |  2 +-
 14 files changed, 36 insertions(+), 49 deletions(-)

-- 
2.25.1