Re: [PATCH] selftests/bpf: close the file descriptor to avoid resource leaks

[Andrii Nakryiko]

On Sun, Mar 23, 2025 at 11:43 PM Malaya Kumar Rout
<malayarout91@xxxxxxxxx> wrote:
>
> Static Analyis for bench_htab_mem.c with cppcheck:error
> tools/testing/selftests/bpf/benchs/bench_htab_mem.c:284:3:
> error: Resource leak: fd [resourceLeak]
> tools/testing/selftests/bpf/prog_tests/sk_assign.c:41:3:
> error: Resource leak: tc [resourceLeak]
>
> fix the issue  by closing the file descriptor (fd & tc) when
> read & fgets operation fails.
>
> Signed-off-by: Malaya Kumar Rout <malayarout91@xxxxxxxxx>
> ---
>  tools/testing/selftests/bpf/benchs/bench_htab_mem.c | 1 +
>  tools/testing/selftests/bpf/prog_tests/sk_assign.c  | 4 +++-
>  2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c
> index 926ee822143e..59746fd2c23a 100644
> --- a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c
> +++ b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c
> @@ -281,6 +281,7 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value)
>         got = read(fd, buf, sizeof(buf) - 1);

It could be a bit cleaner to add close(fd) here and drop the one we
have at the end of the function.

pw-bot: cr

>         if (got <= 0) {
>                 *value = 0;
> +               close(fd);
>                 return;
>         }
>         buf[got] = 0;
> diff --git a/tools/testing/selftests/bpf/prog_tests/sk_assign.c b/tools/testing/selftests/bpf/prog_tests/sk_assign.c
> index 0b9bd1d6f7cc..10a0ab954b8a 100644
> --- a/tools/testing/selftests/bpf/prog_tests/sk_assign.c
> +++ b/tools/testing/selftests/bpf/prog_tests/sk_assign.c
> @@ -37,8 +37,10 @@ configure_stack(void)
>         tc = popen("tc -V", "r");
>         if (CHECK_FAIL(!tc))
>                 return false;
> -       if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
> +       if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc))) {
> +               pclose(tc);

this one looks good

>                 return false;
> +       }
>         if (strstr(tc_version, ", libbpf "))
>                 prog = "test_sk_assign_libbpf.bpf.o";
>         else
> --
> 2.43.0
>