From: Andrii Nakryiko <andrii@kernel.org>
To: <bpf@vger.kernel.org>, <netdev@vger.kernel.org>, <ast@fb.com>,
<daniel@iogearbox.net>
Cc: <andrii@kernel.org>, <kernel-team@fb.com>
Subject: [PATCH v2 bpf-next 07/11] libbpf: fix BTF data layout checks and allow empty BTF
Date: Wed, 4 Nov 2020 20:33:57 -0800 [thread overview]
Message-ID: <20201105043402.2530976-8-andrii@kernel.org> (raw)
In-Reply-To: <20201105043402.2530976-1-andrii@kernel.org>
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 0258cf108c0a..20bb88e71f07 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;
}
- 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;
}
- if (hdr->type_off >= hdr->str_off) {
- pr_debug("BTF type section offset >= string section offset. No type?\n");
- return -EINVAL;
- }
-
- if (hdr->type_off & 0x02) {
+ if (hdr->type_off % 4) {
pr_debug("BTF type section is not aligned to 4 bytes\n");
return -EINVAL;
}
--
2.24.1
next prev parent reply other threads:[~2020-11-05 4:34 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-05 4:33 [PATCH v2 bpf-next 00/11] libbpf: split BTF support Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 01/11] libbpf: factor out common operations in BTF writing APIs Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 02/11] selftest/bpf: relax btf_dedup test checks Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 03/11] libbpf: unify and speed up BTF string deduplication Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 04/11] libbpf: implement basic split BTF support Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 05/11] selftests/bpf: add split BTF basic test Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 06/11] selftests/bpf: add checking of raw type dump in BTF writer APIs selftests Andrii Nakryiko
2020-11-05 4:33 ` Andrii Nakryiko [this message]
2020-11-05 4:33 ` [PATCH v2 bpf-next 08/11] libbpf: support BTF dedup of split BTFs Andrii Nakryiko
2020-11-05 4:33 ` [PATCH v2 bpf-next 09/11] libbpf: accomodate DWARF/compiler bug with duplicated identical arrays Andrii Nakryiko
2020-11-05 4:34 ` [PATCH v2 bpf-next 10/11] selftests/bpf: add split BTF dedup selftests Andrii Nakryiko
2020-11-05 4:34 ` [PATCH v2 bpf-next 11/11] tools/bpftool: add bpftool support for split BTF Andrii Nakryiko
2020-11-05 9:52 ` [PATCH v2 bpf-next 00/11] libbpf: split BTF support Jesper Dangaard Brouer
2020-11-05 19:16 ` Andrii Nakryiko
2020-11-05 19:38 ` Saeed Mahameed
2020-11-05 20:02 ` Andrii Nakryiko
2020-11-06 2:50 ` patchwork-bot+netdevbpf
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