From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 21 Sep 2021 14:00:33 -0700
Subject: libbpf: Fix memory leak in legacy kprobe attach logic
Patch-mainline: v5.16-rc1
Git-commit: 303a257223a3bbd7cc6ccc2b7777179c8d9f3989
References: jsc#PED-1377

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

Fixes: ca304b40c20d ("libbpf: Introduce legacy kprobe events support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-2-andrii@kernel.org
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
 tools/lib/bpf/libbpf.c |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9366,10 +9366,11 @@ bpf_program__attach_kprobe_opts(const st
 						    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);
@@ -9378,7 +9379,7 @@ bpf_program__attach_kprobe_opts(const st
 		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);
@@ -9388,6 +9389,9 @@ bpf_program__attach_kprobe_opts(const st
 	}
 
 	return link;
+err_out:
+	free(legacy_probe);
+	return libbpf_err_ptr(err);
 }
 
 struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,