Re: [PATCH bpf-next v3 5/6] selftests/bpf: Cover BPF program load strategy transitions

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] bpf: bpf_link leaked on selftest error path
--

commit 82f598b63abc74f2a315872de7cd207f7e441280
Author: Slava Imameev <slava.imameev@crowdstrike.com>

selftests/bpf: Cover BPF program load strategy transitions

This commit adds a load_type test to cover BPF program load strategy
transitions. It verifies transitions between DISABLED, AUTO, and MANUAL
strategies, as well as the behavior of autoattach.

> diff --git a/tools/testing/selftests/bpf/prog_tests/load_type.c b/tools/testing/selftests/bpf/prog_tests/load_type.c
> new file mode 100644
> index 0000000000000..55ca53685863c
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/load_type.c
> @@ -0,0 +1,157 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <test_progs.h>
> +#include <time.h>
> +#include "test_load_type.skel.h"
> +
> +void test_load_type(void)
> +{
> +	struct bpf_link *link;
> +	struct test_load_type *skel;

[ ... ]

> +	/* attach prog3 */
> +	link = bpf_program__attach(skel->progs.prog3);
> +	if (!ASSERT_OK_PTR(link, "attach"))
> +		goto cleanup;
> +
> +	usleep(1);
> +
> +	if (!ASSERT_TRUE(skel->bss->prog3_called, "prog3_called_again"))
> +		goto cleanup;

[Severity: Medium]
Will this leak the bpf_link if the assertion fails?

When the test assertion fails, it jumps to the cleanup block in
test_load_type(), skipping the explicit bpf_link__destroy() call. Because
test_load_type__destroy() doesn't clean up manually attached programs,
the link will be leaked.

Also, if you choose to fix this by adding bpf_link__destroy() in the
cleanup block, it looks like the link variable is uninitialized at declaration,
so it might be necessary to initialize it to NULL as well.

> +
> +	/* detach prog3 as test_load_type__destroy doesn't detach manually loaded programs */
> +	err = bpf_link__destroy(link);
> +	ASSERT_OK(err, "link_destroy");
> +
> +cleanup:
> +	test_load_type__destroy(skel);
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260917203040.3150212-1-andrey.grodzovsky@crowdstrike.com?part=5