From: bot+bpf-ci@kernel.org
To: hui.zhu@linux.dev, akpm@linux-foundation.org, hannes@cmpxchg.org,
mhocko@kernel.org, roman.gushchin@linux.dev,
shakeel.butt@linux.dev, muchun.song@linux.dev, ast@kernel.org,
daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev,
eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev,
john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me,
haoluo@google.com, jolsa@kernel.org, shuah@kernel.org,
peterz@infradead.org, ojeda@kernel.org, nathan@kernel.org,
kees@kernel.org, tj@kernel.org, jeffxu@chromium.org,
mkoutny@suse.com, kernel@jfarr.cc, brauner@kernel.org,
rdunlap@infradead.org, brgerst@gmail.com, masahiroy@kernel.org,
davem@davemloft.net, kuba@kernel.org, hawk@kernel.org,
inwardvessel@gmail.com, willemb@google.com,
kerneljasonxing@gmail.com, paul.chaignon@gmail.com,
a.s.protopopov@gmail.com, ameryhung@gmail.com,
chenridong@huaweicloud.com, lance.yang@linux.dev,
jiayuan.chen@linux.dev, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, cgroups@vger.kernel.org, bpf@vger.kernel.org,
netdev@vger.kernel.org, linu@kvack.org,
x-kselftest@vger.kernel.org
Cc: zhuhui@kylinos.cn,geliang@kernel.org,ast@kernel.org,andrii@kernel.org,daniel@iogearbox.net,martin.lau@kernel.org,eddyz87@gmail.com,yonghong.song@linux.dev,clm@meta.com,ihor.solodrai@linux.dev
Subject: Re: [RFC PATCH bpf-next v5 09/12] selftests/bpf: Add tests for memcg_bpf_ops
Date: Tue, 27 Jan 2026 10:08:34 +0000 (UTC) [thread overview]
Message-ID: <34fb17bae65a38450661486263eaffebd488c8943bbf9416e72ba2c0e3b31e07@mail.kernel.org> (raw)
In-Reply-To: <f02bee79100c0df5d799d0d941666b0bf9700ac9.1769506741.git.zhuhui@kylinos.cn>
[-- Attachment #1: Type: text/plain, Size: 1959 bytes --]
> diff --git a/tools/testing/selftests/bpf/prog_tests/memcg_ops.c b/tools/testing/selftests/bpf/prog_tests/memcg_ops.c
> new file mode 100644
> index 000000000000..a596926ea233
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/memcg_ops.c
[ ... ]
> +void test_memcg_ops_over_high(void)
> +{
> + int err, map_fd;
> + struct memcg_ops *skel = NULL;
[ ... ]
> + skel = memcg_ops__open_and_load();
> + if (!ASSERT_OK_PTR(skel, "memcg_ops__open_and_load"))
> + goto out;
[ ... ]
> +out:
> + bpf_link__destroy(link);
> + bpf_link__destroy(link2);
> + memcg_ops__detach(skel);
> + memcg_ops__destroy(skel);
^^^^
Can this cause a NULL pointer dereference? When memcg_ops__open_and_load()
fails, skel is NULL and the code jumps to out: where memcg_ops__detach(skel)
is called. The generated __detach() function does not check for NULL, unlike
__destroy() which does. Since __destroy() already calls __detach() internally
after checking for NULL, the explicit memcg_ops__detach(skel) call appears
to be unnecessary and would crash when skel is NULL.
The same pattern appears in test_memcg_ops_below_low_over_high() and
test_memcg_ops_below_min_over_high().
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/21392729810
AI-authorship-score: medium
AI-authorship-explanation: The commit message uses verbose, explanatory language with markdown formatting that is somewhat atypical for kernel commits, and the repetitive test function structure with the redundant detach call suggests possible AI assistance in code generation.
issues-found: 1
issue-severity-score: low
issue-severity-explanation: The memcg_ops__detach(NULL) call can crash the test if the skeleton fails to load, but this only affects the selftest program and not the kernel itself.
next prev parent reply other threads:[~2026-01-27 10:08 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-27 9:42 [RFC PATCH bpf-next v5 00/12] mm: memcontrol: Add BPF hooks for memory controller Hui Zhu
2026-01-27 9:42 ` [RFC PATCH bpf-next v5 01/12] bpf: move bpf_struct_ops_link into bpf.h Hui Zhu
2026-01-27 9:42 ` [RFC PATCH bpf-next v5 02/12] bpf: initial support for attaching struct ops to cgroups Hui Zhu
2026-01-27 9:42 ` [RFC PATCH bpf-next v5 03/12] bpf: mark struct oom_control's memcg field as TRUSTED_OR_NULL Hui Zhu
2026-01-27 9:42 ` [RFC PATCH bpf-next v5 04/12] mm: define mem_cgroup_get_from_ino() outside of CONFIG_SHRINKER_DEBUG Hui Zhu
2026-01-27 9:42 ` [RFC PATCH bpf-next v5 05/12] libbpf: introduce bpf_map__attach_struct_ops_opts() Hui Zhu
2026-01-27 10:08 ` bot+bpf-ci
2026-01-27 9:45 ` [RFC PATCH bpf-next v5 06/12] bpf: Pass flags in bpf_link_create for struct_ops Hui Zhu
2026-01-27 9:45 ` [RFC PATCH bpf-next v5 07/12] libbpf: Support passing user-defined flags " Hui Zhu
2026-01-27 9:45 ` [RFC PATCH bpf-next v5 08/12] mm: memcontrol: Add BPF struct_ops for memory controller Hui Zhu
2026-01-27 10:08 ` bot+bpf-ci
2026-01-27 9:47 ` [RFC PATCH bpf-next v5 09/12] selftests/bpf: Add tests for memcg_bpf_ops Hui Zhu
2026-01-27 10:08 ` bot+bpf-ci [this message]
2026-01-27 9:47 ` [RFC PATCH bpf-next v5 10/12] mm/bpf: Add BPF_F_ALLOW_OVERRIDE support " Hui Zhu
2026-01-27 10:08 ` bot+bpf-ci
2026-01-27 9:47 ` [RFC PATCH bpf-next v5 11/12] selftests/bpf: Add test for memcg_bpf_ops hierarchies Hui Zhu
2026-01-27 9:48 ` [RFC PATCH bpf-next v5 12/12] samples/bpf: Add memcg priority control example Hui Zhu
2026-01-27 10:08 ` bot+bpf-ci
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=34fb17bae65a38450661486263eaffebd488c8943bbf9416e72ba2c0e3b31e07@mail.kernel.org \
--to=bot+bpf-ci@kernel.org \
--cc=a.s.protopopov@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=ameryhung@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=brauner@kernel.org \
--cc=brgerst@gmail.com \
--cc=cgroups@vger.kernel.org \
--cc=chenridong@huaweicloud.com \
--cc=clm@meta.com \
--cc=daniel@iogearbox.net \
--cc=davem@davemloft.net \
--cc=eddyz87@gmail.com \
--cc=geliang@kernel.org \
--cc=hannes@cmpxchg.org \
--cc=haoluo@google.com \
--cc=hawk@kernel.org \
--cc=hui.zhu@linux.dev \
--cc=ihor.solodrai@linux.dev \
--cc=inwardvessel@gmail.com \
--cc=jeffxu@chromium.org \
--cc=jiayuan.chen@linux.dev \
--cc=john.fastabend@gmail.com \
--cc=jolsa@kernel.org \
--cc=kees@kernel.org \
--cc=kernel@jfarr.cc \
--cc=kerneljasonxing@gmail.com \
--cc=kpsingh@kernel.org \
--cc=kuba@kernel.org \
--cc=lance.yang@linux.dev \
--cc=linu@kvack.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=martin.lau@kernel.org \
--cc=martin.lau@linux.dev \
--cc=masahiroy@kernel.org \
--cc=mhocko@kernel.org \
--cc=mkoutny@suse.com \
--cc=muchun.song@linux.dev \
--cc=nathan@kernel.org \
--cc=netdev@vger.kernel.org \
--cc=ojeda@kernel.org \
--cc=paul.chaignon@gmail.com \
--cc=peterz@infradead.org \
--cc=rdunlap@infradead.org \
--cc=roman.gushchin@linux.dev \
--cc=sdf@fomichev.me \
--cc=shakeel.butt@linux.dev \
--cc=shuah@kernel.org \
--cc=song@kernel.org \
--cc=tj@kernel.org \
--cc=willemb@google.com \
--cc=x-kselftest@vger.kernel.org \
--cc=yonghong.song@linux.dev \
--cc=zhuhui@kylinos.cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox