diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-10-22 17:31:57 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-10-22 17:33:31 -0700 |
| commit | c825f5fee19caf301d9821cd79abaa734322de26 (patch) | |
| tree | 1f6e6c765ae637db277967518e9c5ce58dfe3ca2 /tools/lib | |
| parent | 5245dafe3d49efba4d3285cf27ee1cc1eeafafc6 (diff) | |
| download | linux-c825f5fee19caf301d9821cd79abaa734322de26.tar.bz2 | |
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: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf")
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211023003157.726961-2-andrii@kernel.org
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/btf.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index 05b945208815..ef924fc2c911 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -236,13 +236,19 @@ static int btf_parse_hdr(struct btf *btf) } btf_bswap_hdr(hdr); } 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; } - 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) { - pr_debug("Invalid BTF total size:%u\n", btf->raw_size); + pr_debug("Invalid BTF total size: %u\n", btf->raw_size); return -EINVAL; } |