Commit c825f5fe authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov

libbpf: Fix BTF header parsing checks

Original code assumed fixed and correct BTF header length. That's not
always the case, though, so fix this bug with a proper additional check.
And use actual header length instead of sizeof(struct btf_header) in
sanity checks.

Fixes: 8a138aed ("bpf: btf: Add BTF support to libbpf")
Reported-by: default avatarEvgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211023003157.726961-2-andrii@kernel.org
parent 5245dafe
...@@ -236,13 +236,19 @@ static int btf_parse_hdr(struct btf *btf) ...@@ -236,13 +236,19 @@ static int btf_parse_hdr(struct btf *btf)
} }
btf_bswap_hdr(hdr); btf_bswap_hdr(hdr);
} else if (hdr->magic != BTF_MAGIC) { } else if (hdr->magic != BTF_MAGIC) {
pr_debug("Invalid BTF magic:%x\n", hdr->magic); pr_debug("Invalid BTF magic: %x\n", hdr->magic);
return -EINVAL; return -EINVAL;
} }
meta_left = btf->raw_size - sizeof(*hdr); if (btf->raw_size < hdr->hdr_len) {
pr_debug("BTF header len %u larger than data size %u\n",
hdr->hdr_len, btf->raw_size);
return -EINVAL;
}
meta_left = btf->raw_size - hdr->hdr_len;
if (meta_left < (long long)hdr->str_off + hdr->str_len) { if (meta_left < (long long)hdr->str_off + hdr->str_len) {
pr_debug("Invalid BTF total size:%u\n", btf->raw_size); pr_debug("Invalid BTF total size: %u\n", btf->raw_size);
return -EINVAL; return -EINVAL;
} }
......
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