From: Song Liu <songliubraving@fb.com>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf <bpf@vger.kernel.org>, Networking <netdev@vger.kernel.org>,
"Alexei Starovoitov" <ast@fb.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Kernel Team <Kernel-team@fb.com>
Subject: Re: [PATCH bpf-next 07/11] libbpf: fix BTF data layout checks and allow empty BTF
Date: Tue, 3 Nov 2020 00:51:36 +0000 [thread overview]
Message-ID: <DC33E827-1A58-4AFF-A91B-138FBC8728A6@fb.com> (raw)
In-Reply-To: <20201029005902.1706310-8-andrii@kernel.org>
> On Oct 28, 2020, at 5:58 PM, Andrii Nakryiko <andrii@kernel.org> wrote:
>
> Make data section layout checks stricter, disallowing overlap of types and
> strings data.
>
> Additionally, allow BTFs with no type data. There is nothing inherently wrong
> with having BTF with no types (put potentially with some strings). This could
> be a situation with kernel module BTFs, if module doesn't introduce any new
> type information.
>
> Also fix invalid offset alignment check for btf->hdr->type_off.
>
> Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf")
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> ---
> tools/lib/bpf/btf.c | 16 ++++++----------
> 1 file changed, 6 insertions(+), 10 deletions(-)
>
> diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
> index 20c64a8441a8..9b0ef71a03d0 100644
> --- a/tools/lib/bpf/btf.c
> +++ b/tools/lib/bpf/btf.c
> @@ -245,22 +245,18 @@ static int btf_parse_hdr(struct btf *btf)
> return -EINVAL;
> }
>
> - if (meta_left < hdr->type_off) {
> - pr_debug("Invalid BTF type section offset:%u\n", hdr->type_off);
> + if (meta_left < hdr->str_off + hdr->str_len) {
> + pr_debug("Invalid BTF total size:%u\n", btf->raw_size);
> return -EINVAL;
> }
Can we make this one as
if (meta_left != hdr->str_off + hdr->str_len) {
>
> - if (meta_left < hdr->str_off) {
> - pr_debug("Invalid BTF string section offset:%u\n", hdr->str_off);
> + if (hdr->type_off + hdr->type_len > hdr->str_off) {
> + pr_debug("Invalid BTF data sections layout: type data at %u + %u, strings data at %u + %u\n",
> + hdr->type_off, hdr->type_len, hdr->str_off, hdr->str_len);
> return -EINVAL;
> }
And this one
if (hdr->type_off + hdr->type_len != hdr->str_off) {
?
[...]
next prev parent reply other threads:[~2020-11-03 0:51 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-29 0:58 [PATCH bpf-next 00/11] libbpf: split BTF support Andrii Nakryiko
2020-10-29 0:58 ` [PATCH bpf-next 01/11] libbpf: factor out common operations in BTF writing APIs Andrii Nakryiko
2020-10-30 0:36 ` Song Liu
2020-10-29 0:58 ` [PATCH bpf-next 02/11] selftest/bpf: relax btf_dedup test checks Andrii Nakryiko
2020-10-30 16:43 ` Song Liu
2020-10-30 18:44 ` Andrii Nakryiko
2020-10-30 22:30 ` Song Liu
2020-10-29 0:58 ` [PATCH bpf-next 03/11] libbpf: unify and speed up BTF string deduplication Andrii Nakryiko
2020-10-30 23:32 ` Song Liu
2020-11-03 4:51 ` Andrii Nakryiko
2020-11-03 4:59 ` Alexei Starovoitov
2020-11-03 6:01 ` Andrii Nakryiko
2020-10-29 0:58 ` [PATCH bpf-next 04/11] libbpf: implement basic split BTF support Andrii Nakryiko
2020-11-02 23:23 ` Song Liu
2020-11-03 5:02 ` Andrii Nakryiko
2020-11-03 5:41 ` Song Liu
2020-11-04 23:51 ` Andrii Nakryiko
2020-10-29 0:58 ` [PATCH bpf-next 05/11] selftests/bpf: add split BTF basic test Andrii Nakryiko
2020-11-02 23:36 ` Song Liu
2020-11-03 5:10 ` Andrii Nakryiko
2020-10-29 0:58 ` [PATCH bpf-next 06/11] selftests/bpf: add checking of raw type dump in BTF writer APIs selftests Andrii Nakryiko
2020-11-03 0:08 ` Song Liu
2020-11-03 5:14 ` Andrii Nakryiko
2020-10-29 0:58 ` [PATCH bpf-next 07/11] libbpf: fix BTF data layout checks and allow empty BTF Andrii Nakryiko
2020-11-03 0:51 ` Song Liu [this message]
2020-11-03 5:18 ` Andrii Nakryiko
2020-11-03 5:44 ` Song Liu
2020-10-29 0:58 ` [PATCH bpf-next 08/11] libbpf: support BTF dedup of split BTFs Andrii Nakryiko
2020-11-03 2:49 ` Song Liu
2020-11-03 5:25 ` Andrii Nakryiko
2020-11-03 5:59 ` Song Liu
2020-11-03 6:31 ` Andrii Nakryiko
2020-11-03 17:15 ` Song Liu
2020-11-03 5:10 ` Alexei Starovoitov
2020-11-03 6:27 ` Andrii Nakryiko
2020-11-03 17:55 ` Alexei Starovoitov
2020-10-29 0:59 ` [PATCH bpf-next 09/11] libbpf: accomodate DWARF/compiler bug with duplicated identical arrays Andrii Nakryiko
2020-11-03 2:52 ` Song Liu
2020-10-29 0:59 ` [PATCH bpf-next 10/11] selftests/bpf: add split BTF dedup selftests Andrii Nakryiko
2020-11-03 5:35 ` Song Liu
2020-11-03 6:05 ` Andrii Nakryiko
2020-11-03 6:30 ` Song Liu
2020-10-29 0:59 ` [PATCH bpf-next 11/11] tools/bpftool: add bpftool support for split BTF Andrii Nakryiko
2020-11-03 6:03 ` Song Liu
2020-10-30 0:33 ` [PATCH bpf-next 00/11] libbpf: split BTF support Song Liu
2020-10-30 2:33 ` Andrii Nakryiko
2020-10-30 6:45 ` Song Liu
2020-10-30 12:04 ` Alan Maguire
2020-10-30 18:30 ` Andrii Nakryiko
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