Re: [PATCH bpf-next 4/5] selftest/bpf: Fix memory leak in kprobe_multi_test

On Sun, Oct 09, 2022 at 09:18:29AM -0400, Xu Kuohai wrote:

From: Xu Kuohai xukuohai@huawei.com

The get_syms() function in kprobe_multi_test.c does not free the string memory allocated by sscanf correctly. Fix it.

Signed-off-by: Xu Kuohai xukuohai@huawei.com

.../bpf/prog_tests/kprobe_multi_test.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index d457a55ff408..07dd2c5b7f98 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -360,15 +360,14 @@ static int get_syms(char ***symsp, size_t *cntp) * to them. Filter out the current culprits - arch_cpu_idle * and rcu_* functions. */

• if (!strcmp(name, "arch_cpu_idle"))
  

• 	continue;
  

• if (!strncmp(name, "rcu_", 4))
  

• 	continue;
  

• if (!strcmp(name, "bpf_dispatcher_xdp_func"))
  

• 	continue;
  

• if (!strncmp(name, "__ftrace_invalid_address__",
  

• 	     sizeof("__ftrace_invalid_address__") - 1))
  

• if (!strcmp(name, "arch_cpu_idle") ||
  

• 	!strncmp(name, "rcu_", 4) ||
  

• 	!strcmp(name, "bpf_dispatcher_xdp_func") ||
  

• 	!strncmp(name, "__ftrace_invalid_address__",
  

• 		 sizeof("__ftrace_invalid_address__") - 1)) {
  

• 	free(name);
  continue;
  

• }
  

  err = hashmap__add(map, name, NULL); if (err) { free(name);

@@ -394,7 +393,7 @@ static int get_syms(char ***symsp, size_t *cntp) hashmap__free(map); if (err) { for (i = 0; i < cnt; i++)

• 	free(syms[cnt]);
  

• 	free(syms[i]);
  

mama mia.. nice catch! thanks

Acked-by: Jiri Olsa jolsa@kernel.org

jirka

free(syms);

} return err; -- 2.25.1