On Tue, Jul 12, 2022 at 10:57:45AM +0800, Hengqi Chen wrote:
> binary_path is a required non-null parameter for bpf_program__attach_usdt
> and bpf_program__attach_uprobe_opts. Check it against NULL to prevent
> coredump on strchr.
binary_path seems to be mandatory so LGTM, cc-ing Alan to be sure ;-)
thanks,
jirka
>
> Signed-off-by: Hengqi Chen <hengqi.chen@xxxxxxxxx>
> ---
> tools/lib/bpf/libbpf.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index cb49408eb298..72548798126b 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -10545,7 +10545,10 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
> ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0);
> pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
>
> - if (binary_path && !strchr(binary_path, '/')) {
> + if (!binary_path)
> + return libbpf_err_ptr(-EINVAL);
> +
> + if (!strchr(binary_path, '/')) {
> err = resolve_full_path(binary_path, full_binary_path,
> sizeof(full_binary_path));
> if (err) {
> @@ -10559,11 +10562,6 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
> if (func_name) {
> long sym_off;
>
> - if (!binary_path) {
> - pr_warn("prog '%s': name-based attach requires binary_path\n",
> - prog->name);
> - return libbpf_err_ptr(-EINVAL);
> - }
> sym_off = elf_find_func_offset(binary_path, func_name);
> if (sym_off < 0)
> return libbpf_err_ptr(sym_off);
> @@ -10711,6 +10709,9 @@ struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog,
> return libbpf_err_ptr(-EINVAL);
> }
>
> + if (!binary_path)
> + return libbpf_err_ptr(-EINVAL);
> +
> if (!strchr(binary_path, '/')) {
> err = resolve_full_path(binary_path, resolved_path, sizeof(resolved_path));
> if (err) {
> --
> 2.30.2
