From 7129e266643883a4f83e65fce3ce20c7f7269fb3 Mon Sep 17 00:00:00 2001 From: Paul Moses Date: Tue, 9 Jun 2026 05:08:54 -0500 Subject: [PATCH bpf] selftests/bpf: Add BTF repeated field count overflow test Add a raw BTF test that exercises repeated special-field expansion with a large array count. The compact element layout keeps the array byte size representable while the repeated field count overflows the old u32 capacity calculation in btf_repeat_fields(). Signed-off-by: Paul Moses --- tools/testing/selftests/bpf/prog_tests/btf.c | 37 ++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 054ecb6b1e9f..9fcbc554e351 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -4258,6 +4258,43 @@ static struct btf_raw_test raw_tests[] = { .max_entries = 1, }, +{ + .descr = "struct test repeated fields count overflow", + .raw_types = { + BTF_TYPE_INT_ENC(NAME_TBD, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_STRUCT_ENC(NAME_TBD, 0, 0), /* [2] */ + BTF_TYPE_TAG_ENC(NAME_TBD, 2), /* [3] */ + BTF_PTR_ENC(3), /* [4] */ + BTF_TYPE_ARRAY_ENC(4, 1, 1), /* [5] */ + BTF_STRUCT_ENC(NAME_TBD, 10, 8), /* [6] */ + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_TYPE_ARRAY_ENC(6, 1, 0x1999999aU), /* [7] */ + BTF_STRUCT_ENC(NAME_TBD, 2, 8 + 8 * 0x1999999aU), /* [8] */ + BTF_MEMBER_ENC(NAME_TBD, 4, 0), + BTF_MEMBER_ENC(NAME_TBD, 7, 64), + BTF_END_RAW, + }, + BTF_STR_SEC("\0int\0prog_test_ref_kfunc\0kptr_untrusted\0elem" + "\0p0\0p1\0p2\0p3\0p4\0p5\0p6\0p7\0p8\0p9" + "\0outer\0trigger\0elems"), + .map_type = BPF_MAP_TYPE_ARRAY, + .map_name = "repeat_fields", + .key_size = sizeof(int), + .value_size = 8 + 8 * 0x1999999aU, + .key_type_id = 1, + .value_type_id = 8, + .max_entries = 1, + .btf_load_err = true, +}, }; /* struct btf_raw_test raw_tests[] */ static const char *get_next_str(const char *start, const char *end) -- 2.54.0