We don't check if cookies are available on the kprobe_multi link before accessing them in show_fdinfo callback, we should. Cc: stable@vger.kernel.org Fixes: da7e9c0a7fbc ("bpf: Add show_fdinfo for kprobe_multi") Signed-off-by: Jiri Olsa --- kernel/trace/bpf_trace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 9bc0dfd235af..0b040a417442 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2454,8 +2454,10 @@ static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link, struct seq_file *seq) { struct bpf_kprobe_multi_link *kmulti_link; + bool has_cookies; kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); + has_cookies = !!kmulti_link->cookies; seq_printf(seq, "kprobe_cnt:\t%u\n" @@ -2467,7 +2469,7 @@ static void bpf_kprobe_multi_show_fdinfo(const struct bpf_link *link, for (int i = 0; i < kmulti_link->cnt; i++) { seq_printf(seq, "%llu\t %pS\n", - kmulti_link->cookies[i], + has_cookies ? kmulti_link->cookies[i] : 0, (void *)kmulti_link->addrs[i]); } } -- 2.53.0