wireguard-linux/tools/testing/selftests/bpf/prog_tests/signed_loader.c, branch stableWireGuard for the Linux kernelhttps://git.zx2c4.com/wireguard-linux/atom/tools/testing/selftests/bpf/prog_tests/signed_loader.c?h=stable2026-07-08T18:44:33Zselftests/bpf: Close fd on unexpected success in signed loader2026-07-08T18:44:33ZDaniel Borkmanndaniel@iogearbox.net2026-07-08T18:41:07Zurn:sha1:43f129d2148983f69f8f9c34f2a64d27f888bef1
The signature_enforced, signature_too_large, signature_zero_size and
signature_bad_keyring subtests load a program that must be rejected,
but leave the fd open if the kernel unexpectedly accepts the load:
test_progs asserts record the failure and continue, so the fd would
linger for the rest of the run. Just close it.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708184107.369182-1-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
selftests/bpf: Verify load-time signed loader metadata2026-07-08T18:05:13ZDaniel Borkmanndaniel@iogearbox.net2026-07-08T07:53:42Zurn:sha1:99b321dde704e38d3e6c1f425613d7b138ba5696
The signed gen_loader no longer checks its metadata map from within
BPF; the kernel does it at BPF_PROG_LOAD by folding the loader's frozen
exclusive fd_array maps into the signature. Exercise that path end to
end. Extend with more test cases (e.g. map-less program, asserting the
LSM admission hook observes BPF_SIG_UNSIGNED and BPF_SIG_VERIFIED), and
retire the subtests that asserted the old in-loader check, which no
longer exists.
# LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t signed_loader
[...]
#412/1 signed_loader/loadtime_no_map:OK
#412/2 signed_loader/loadtime_with_map:OK
#412/3 signed_loader/metadata_match:OK
#412/4 signed_loader/signature_enforced:OK
#412/5 signed_loader/signed_nonexcl_fd_array_rejected:OK
#412/6 signed_loader/signed_unfrozen_fd_array_rejected:OK
#412/7 signed_loader/signed_nonarray_fd_array_rejected:OK
#412/8 signed_loader/signed_btf_fd_array_rejected:OK
#412/9 signed_loader/signed_module_kfunc_rejected:OK
#412/10 signed_loader/signature_failure_logs:OK
#412/11 signed_loader/signature_too_large:OK
#412/12 signed_loader/signature_zero_size:OK
#412/13 signed_loader/signature_bad_keyring:OK
#412/14 signed_loader/metadata_ctx_max_entries_ignored:OK
#412/15 signed_loader/metadata_ctx_initial_value_ignored:OK
#412/16 signed_loader/signature_authenticates_insns:OK
#412/17 signed_loader/signature_authenticates_metadata:OK
#412/18 signed_loader/hash_requires_frozen:OK
#412/19 signed_loader/no_update_after_freeze:OK
#412/20 signed_loader/freeze_writable_mmap:OK
#412/21 signed_loader/no_writable_mmap_frozen:OK
#412/22 signed_loader/map_hash_matches_libbpf:OK
#412/23 signed_loader/map_hash_multi_element:OK
#412/24 signed_loader/map_hash_bad_size:OK
#412/25 signed_loader/map_hash_unsupported_type:OK
#412/26 signed_loader/lsm_signature_verdict:OK
#412/27 signed_loader/signed_no_fd_array:OK
#412/28 signed_loader/signed_map_by_fd_rejected:OK
#412/29 signed_loader/signed_sparse_fd_array_rejected:OK
#412 signed_loader:OK
Summary: 1/29 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708075343.358712-8-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
selftests/bpf: Inspect the signature verdict exposed to BPF LSM2026-06-06T03:33:48ZDaniel Borkmanndaniel@iogearbox.net2026-06-05T21:35:18Zurn:sha1:8ddce416797b7454ba1df855821b02c6e43b5a0e
Add a minimal BPF LSM program on lsm/bpf_prog_load that, for loads on
the monitored thread, reads back prog->aux->sig.{verdict,keyring_type,
keyring_serial}, and a signed_loader subtest that drives the same
gen_loader loader through the hook twice: i) /unsigned/ where the LSM
must observe UNSIGNED, no keyring and serial 0; ii) /signed/ where the
very same insns signed against the session keyring must be observed as
VERIFIED with a user keyring, and the recorded keyring_serial must be
equal to the resolved session keyring serial. Loading (not running) the
loader is sufficient since the verdict is attached at load time.
# LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t signed_loader
[ 1.970530] clocksource: Switched to clocksource tsc
#405/1 signed_loader/metadata_check_shape:OK
#405/2 signed_loader/metadata_match:OK
#405/3 signed_loader/metadata_sha_mismatch:OK
#405/4 signed_loader/metadata_not_exclusive:OK
#405/5 signed_loader/metadata_hash_not_computed:OK
#405/6 signed_loader/signature_enforced:OK
#405/7 signed_loader/signature_too_large:OK
#405/8 signed_loader/signature_bad_keyring:OK
#405/9 signed_loader/metadata_ctx_max_entries_ignored:OK
#405/10 signed_loader/metadata_ctx_initial_value_ignored:OK
#405/11 signed_loader/signature_authenticates_insns:OK
#405/12 signed_loader/hash_requires_frozen:OK
#405/13 signed_loader/no_update_after_freeze:OK
#405/14 signed_loader/freeze_writable_mmap:OK
#405/15 signed_loader/no_writable_mmap_frozen:OK
#405/16 signed_loader/map_hash_matches_libbpf:OK
#405/17 signed_loader/map_hash_multi_element:OK
#405/18 signed_loader/map_hash_bad_size:OK
#405/19 signed_loader/map_hash_unsupported_type:OK
#405/20 signed_loader/lsm_signature_verdict:OK
#405 signed_loader:OK
Summary: 1/20 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260605213518.544262-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
selftests/bpf: Test signed loader error paths2026-06-04T16:44:43ZDaniel Borkmanndaniel@iogearbox.net2026-06-03T21:16:58Zurn:sha1:5b88319e4775ee1924d5b709084b25f72e6fe78d
The positive path for signed BPF loaders is covered today by the
signed lskels (fentry_test, fexit_test, atomics).
But the runtime metadata check the generated loader performs (libbpf
gen_loader's emit_signature_match), the map content hash it relies
on, the load-time signature, and the immutability invariants of its
metadata map are not yet covered.
Thus, add a new, extensive test suite which drives libbpf's gen_loader
(bpf_object__gen_loader, gen_hash=true), the same machinery which
bpftool uses for signed light skeletons, and exercise corner cases
so that we can assert this in BPF CI:
# LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t signed_loader
[...]
[ 1.840842] clocksource: Switched to clocksource tsc
#405/1 signed_loader/metadata_check_shape:OK
#405/2 signed_loader/metadata_match:OK
#405/3 signed_loader/metadata_sha_mismatch:OK
#405/4 signed_loader/metadata_not_exclusive:OK
#405/5 signed_loader/metadata_hash_not_computed:OK
#405/6 signed_loader/signature_enforced:OK
#405/7 signed_loader/signature_too_large:OK
#405/8 signed_loader/signature_bad_keyring:OK
#405/9 signed_loader/metadata_ctx_max_entries_ignored:OK
#405/10 signed_loader/metadata_ctx_initial_value_ignored:OK
#405/11 signed_loader/signature_authenticates_insns:OK
#405/12 signed_loader/hash_requires_frozen:OK
#405/13 signed_loader/no_update_after_freeze:OK
#405/14 signed_loader/freeze_writable_mmap:OK
#405/15 signed_loader/no_writable_mmap_frozen:OK
#405/16 signed_loader/map_hash_matches_libbpf:OK
#405/17 signed_loader/map_hash_multi_element:OK
#405/18 signed_loader/map_hash_bad_size:OK
#405/19 signed_loader/map_hash_unsupported_type:OK
#405 signed_loader:OK
Summary: 1/19 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20260603211658.471212-2-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>