Re: [PATCH bpf] selftests/bpf: Fix resource leak in serial_test_wq on attach failure

[Yonghong Song]

On 1/21/26 9:49 AM, Kery Qi wrote:
> Hi,
>
> Thank you for the review.
>
> You are completely right regarding wq__open_and_load(): if it fails,
> it returns NULL and performs its own cleanup, so an immediate return
> is correct there.
>
> However, my concern is about the next step: wq__attach(wq_skel).
>
> If wq__open_and_load() succeeds, wq_skel is allocated. If wq__attach()
> subsequently fails, the original code returns immediately without
> calling wq__destroy(wq_skel), which causes a memory leak of the
> skeleton object.
>
> The proposed goto clean_up is intended to ensure wq__destroy(wq_skel)
> is called specifically when wq__attach() fails.
>
> Does that make sense?

Yes.

> Best regards,
>
> Kery
>
> Yonghong Song <yonghong.song@xxxxxxxxx> 于2026年1月21日周三 23:45写道：
> > On 1/21/26 1:41 AM, Kery Qi wrote:
> > > When wq__attach() fails, serial_test_wq() returns early without calling
> > > wq__destroy(), leaking the skeleton resources allocated by
> > > wq__open_and_load(). This causes ASAN leak reports in selftests runs.
> > >
> > > Fix this by jumping to a common clean_up label that calls wq__destroy()
> > > on all exit paths after successful open_and_load.
> > >
> > > Note that the early return after wq__open_and_load() failure is correct
> > > and doesn't need fixing, since that function returns NULL on failure
> > > (after internally cleaning up any partial allocations).
> > >
> > > Fixes: 8290dba51910 ("selftests/bpf: wq: add bpf_wq_start() checks")
> > > Signed-off-by: Kery Qi <qikeyu2017@xxxxxxxxx>
> > Acked-by: Yonghong Song <yonghong.song@xxxxxxxxx>