diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-10-22 17:31:57 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-18 14:04:10 +0100 |
| commit | 50fcaa7155214dbc57c985bb55edb1eb8e880fdb (patch) | |
| tree | 5f09cb514939c46784df51c9de0b2f9617d9ecc2 /tools | |
| parent | 12872fd7e40b08c92c90da6f7c16a11a65b68aa2 (diff) | |
libbpf: Fix BTF header parsing checks
[ Upstream commit c825f5fee19caf301d9821cd79abaa734322de26 ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools')
| -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 c15eb14a711e..e6f644cdc9f1 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -205,13 +205,19 @@ 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; } |