Commit 303a2572 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
Browse files

libbpf: Fix memory leak in legacy kprobe attach logic 



In some error scenarios legacy_probe string won't be free()'d. Fix this.
This was reported by Coverity static analysis.

Fixes: ca304b40 ("libbpf: Introduce legacy kprobe events support")
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-2-andrii@kernel.org
parent cf8980a3

tools/lib/bpf/libbpf.c

+7 −3
Original line number Diff line number Diff line
@@ -9365,10 +9365,11 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 
						    offset, -1 /* pid */);

	}

	if (pfd < 0) {

		err = pfd;

		pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",

			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,

			libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));

		return libbpf_err_ptr(pfd);

			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));

		goto err_out;

	}

	link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);

	err = libbpf_get_error(link);
@@ -9377,7 +9378,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 
		pr_warn("prog '%s': failed to attach to %s '%s': %s\n",

			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,

			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));

		return libbpf_err_ptr(err);

		goto err_out;

	}

	if (legacy) {

		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
@@ -9387,6 +9388,9 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, 
	}



	return link;

err_out:

	free(legacy_probe);

	return libbpf_err_ptr(err);

}



struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,