* [PATCH bpf] selftests/bpf: Add BTF repeated field count overflow test
@ 2026-06-09 11:37 Paul Moses
2026-06-09 16:47 ` Eduard Zingerman
0 siblings, 1 reply; 3+ messages in thread
From: Paul Moses @ 2026-06-09 11:37 UTC (permalink / raw)
To: martin.lau, ast, daniel, andrii, eddyz87, memxor, bpf
Cc: song, yonghong.song, jolsa, houtao1, linux-kernel, Paul Moses,
stable
From 7129e266643883a4f83e65fce3ce20c7f7269fb3 Mon Sep 17 00:00:00 2001
From: Paul Moses <p@1g4.org>
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 <p@1g4.org>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH bpf] selftests/bpf: Add BTF repeated field count overflow test
2026-06-09 11:37 [PATCH bpf] selftests/bpf: Add BTF repeated field count overflow test Paul Moses
@ 2026-06-09 16:47 ` Eduard Zingerman
2026-06-09 18:08 ` Alexei Starovoitov
0 siblings, 1 reply; 3+ messages in thread
From: Eduard Zingerman @ 2026-06-09 16:47 UTC (permalink / raw)
To: Paul Moses, martin.lau, ast, daniel, andrii, memxor, bpf
Cc: song, yonghong.song, jolsa, houtao1, linux-kernel, stable
On Tue, 2026-06-09 at 11:37 +0000, Paul Moses wrote:
> From 7129e266643883a4f83e65fce3ce20c7f7269fb3 Mon Sep 17 00:00:00 2001
> From: Paul Moses <p@1g4.org>
> 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 <p@1g4.org>
> ---
Note that this selftest is depending on a fix:
https://lore.kernel.org/bpf/DJ4DWMO4HXCM.3NVLDGNT2704E@gmail.com/T/#t
W/o the fix KASAN warning is reported when executing the test.
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
[...]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH bpf] selftests/bpf: Add BTF repeated field count overflow test
2026-06-09 16:47 ` Eduard Zingerman
@ 2026-06-09 18:08 ` Alexei Starovoitov
0 siblings, 0 replies; 3+ messages in thread
From: Alexei Starovoitov @ 2026-06-09 18:08 UTC (permalink / raw)
To: Eduard Zingerman, Paul Moses, martin.lau, ast, daniel, andrii,
memxor, bpf
Cc: song, yonghong.song, jolsa, houtao1, linux-kernel, stable
On Tue Jun 9, 2026 at 9:47 AM PDT, Eduard Zingerman wrote:
> On Tue, 2026-06-09 at 11:37 +0000, Paul Moses wrote:
>> From 7129e266643883a4f83e65fce3ce20c7f7269fb3 Mon Sep 17 00:00:00 2001
>> From: Paul Moses <p@1g4.org>
>> 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 <p@1g4.org>
>> ---
>
> Note that this selftest is depending on a fix:
> https://lore.kernel.org/bpf/DJ4DWMO4HXCM.3NVLDGNT2704E@gmail.com/T/#t
> W/o the fix KASAN warning is reported when executing the test.
>
> Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Pls resubmit both together.
pw-bot: cr
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2026-06-09 11:37 [PATCH bpf] selftests/bpf: Add BTF repeated field count overflow test Paul Moses
2026-06-09 16:47 ` Eduard Zingerman
2026-06-09 18:08 ` Alexei Starovoitov
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