> On May 29, 2019, at 10:36 AM, Andrii Nakryiko <andriin@xxxxxx> wrote:
>
> Ensure that size of a section w/ BPF instruction is exactly a multiple
> of BPF instruction size.
>
> Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index ca4432f5b067..c6c9d632624a 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -349,8 +349,11 @@ static int
> bpf_program__init(void *data, size_t size, char *section_name, int idx,
> struct bpf_program *prog)
> {
> - if (size < sizeof(struct bpf_insn)) {
> - pr_warning("corrupted section '%s'\n", section_name);
> + const size_t bpf_insn_sz = sizeof(struct bpf_insn);
> +
> + if (size == 0 || size % bpf_insn_sz) {
> + pr_warning("corrupted section '%s', size: %zu\n",
> + section_name, size);
> return -EINVAL;
> }
>
> @@ -376,9 +379,8 @@ bpf_program__init(void *data, size_t size, char *section_name, int idx,
> section_name);
> goto errout;
> }
> - prog->insns_cnt = size / sizeof(struct bpf_insn);
> - memcpy(prog->insns, data,
> - prog->insns_cnt * sizeof(struct bpf_insn));
> + prog->insns_cnt = size / bpf_insn_sz;
> + memcpy(prog->insns, data, size);
> prog->idx = idx;
> prog->instances.fds = NULL;
> prog->instances.nr = -1;
> --
> 2.17.1
>
