From 303a257223a3bbd7cc6ccc2b7777179c8d9f3989 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Tue, 21 Sep 2021 14:00:33 -0700 Subject: [PATCH] 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: ca304b40c20d ("libbpf: Introduce legacy kprobe events support") Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210921210036.1545557-2-andrii@kernel.org --- tools/lib/bpf/libbpf.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index da65a1666a5e..6d2f12db6034 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -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,