diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2021-11-24 01:23:14 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2021-11-26 00:14:06 +0100 |
| commit | 401891a9debaf0a684502f2aaecf53448cee9414 (patch) | |
| tree | 0aa7859715d0c72758e24fe0d0665f5adad02528 /tools/lib/bpf | |
| parent | tools/resolve_btf_ids: Close ELF file on error (diff) | |
| download | linux-401891a9debaf0a684502f2aaecf53448cee9414.tar.xz linux-401891a9debaf0a684502f2aaecf53448cee9414.zip | |
libbpf: Fix potential misaligned memory access in btf_ext__new()
Perform a memory copy before we do the sanity checks of btf_ext_hdr.
This prevents misaligned memory access if raw btf_ext data is not 4-byte
aligned ([0]).
While at it, also add missing const qualifier.
[0] Closes: https://github.com/libbpf/libbpf/issues/391
Fixes: 2993e0515bb4 ("tools/bpf: add support to read .BTF.ext sections")
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211124002325.1737739-3-andrii@kernel.org
Diffstat (limited to 'tools/lib/bpf')
| -rw-r--r-- | tools/lib/bpf/btf.c | 10 | ||||
| -rw-r--r-- | tools/lib/bpf/btf.h | 2 |
2 files changed, 6 insertions, 6 deletions
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index e97217a77196..8024fe355ca8 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -2731,15 +2731,11 @@ void btf_ext__free(struct btf_ext *btf_ext) free(btf_ext); } -struct btf_ext *btf_ext__new(__u8 *data, __u32 size) +struct btf_ext *btf_ext__new(const __u8 *data, __u32 size) { struct btf_ext *btf_ext; int err; - err = btf_ext_parse_hdr(data, size); - if (err) - return libbpf_err_ptr(err); - btf_ext = calloc(1, sizeof(struct btf_ext)); if (!btf_ext) return libbpf_err_ptr(-ENOMEM); @@ -2752,6 +2748,10 @@ struct btf_ext *btf_ext__new(__u8 *data, __u32 size) } memcpy(btf_ext->data, data, size); + err = btf_ext_parse_hdr(btf_ext->data, size); + if (err) + goto done; + if (btf_ext->hdr->hdr_len < offsetofend(struct btf_ext_header, line_info_len)) { err = -EINVAL; goto done; diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 5c73a5b0a044..742a2bf71c5e 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -157,7 +157,7 @@ LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name, __u32 expected_value_size, __u32 *key_type_id, __u32 *value_type_id); -LIBBPF_API struct btf_ext *btf_ext__new(__u8 *data, __u32 size); +LIBBPF_API struct btf_ext *btf_ext__new(const __u8 *data, __u32 size); LIBBPF_API void btf_ext__free(struct btf_ext *btf_ext); LIBBPF_API const void *btf_ext__get_raw_data(const struct btf_ext *btf_ext, __u32 *size); |