We currently search for 'bpf-gcc' and 'bpf-none-gcc'. Gentoo's
sys-devel/bpf-toolchain package uses 'bpf-unknown-none-gcc', as does Fedora's
cross-binutils. Search for this name too.
When built with ACL support, we might be processing a tmpfiles
entry where there's no cause for us to call parse_acls_from_arg,
then we get to the end of parse_line without having ever populated
i.{acl_access, acl_default}.
Then we pass a null pointer into acl_free().
From UBSAN w/ GCC 13.0.0_pre20230101:
```
$ systemd-tmpfiles --clean
/var/tmp/portage/sys-apps/acl-2.3.1-r1/work/acl-2.3.1/libacl/acl_free.c:44:14: runtime error: applying non-zero offset 18446744073709551608 to null pointer
#0 0x7f65d868b482 in acl_free /var/tmp/portage/sys-apps/acl-2.3.1-r1/work/acl-2.3.1/libacl/acl_free.c:44
#1 0x55fe7e592249 in item_free_contents ../systemd-9999/src/tmpfiles/tmpfiles.c:2855
#2 0x55fe7e5a347a in parse_line ../systemd-9999/src/tmpfiles/tmpfiles.c:3158
#3 0x55fe7e5a347a in read_config_file ../systemd-9999/src/tmpfiles/tmpfiles.c:3897
#4 0x55fe7e590c61 in read_config_files ../systemd-9999/src/tmpfiles/tmpfiles.c:3985
#5 0x55fe7e590c61 in run ../systemd-9999/src/tmpfiles/tmpfiles.c:4157
#6 0x55fe7e590c61 in main ../systemd-9999/src/tmpfiles/tmpfiles.c:4218
#7 0x7f65d7ebe289 (/usr/lib64/libc.so.6+0x23289)
#8 0x7f65d7ebe344 in __libc_start_main (/usr/lib64/libc.so.6+0x23344)
#9 0x55fe7e591900 in _start (/usr/bin/systemd-tmpfiles+0x11900)
```
We only allow a selected subset of syscalls from nspawn containers
and don't list any time64 variants (needed for 32-bit arches when
built using TIME_BITS=64, which is relatively new).
We allow sched_rr_get_interval which cpython's test suite makes
use of, but we don't allow sched_rr_get_interval_time64.
The test failures when run in an arm32 nspawn container on an arm64 host
were as follows:
```
======================================================================
ERROR: test_sched_rr_get_interval (test.test_posix.PosixTester.test_sched_rr_get_interval)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/var/tmp/portage/dev-lang/python-3.11.0_p1/work/Python-3.11.0/Lib/test/test_posix.py", line 1180, in test_sched_rr_get_interval
interval = posix.sched_rr_get_interval(0)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
PermissionError: [Errno 1] Operation not permitted
```
Then strace showed:
```
sched_rr_get_interval_time64(0, 0xffbbd4a0) = -1 EPERM (Operation not permitted)
```
This appears to be the only time64 syscall that isn't already included one of
the sets listed in nspawn-seccomp.c that has a non-time64 variant. Checked
over each of the time64 syscalls known to systemd and verified that none
of the others had a non-time64-variant whitelisted in nspawn other than
sched_rr_get_interval.
Bug: https://bugs.gentoo.org/880131
Sam James