Re: [PATCH 1/4] mm: kmemleak: confirm suspected leaks with a second scan

[Geert Uytterhoeven]

Hi Breno,

On Mon, 13 Jul 2026 at 13:48, Breno Leitao <leitao@xxxxxxxxxx> wrote:
> From: Catalin Marinas <catalin.marinas@xxxxxxx>
>
> The kmemleak marking phase is not atomic. While the object graph is
> traversed, the kernel can modify pointers, free objects or allocate new
> ones. If a reference to an object is moved from one location to another,
> kmemleak scanning may miss it. We have explicit annotations like
> kmemleak_transient_leak() but identifying and maintaining them is not
> trivial.
>
> Given that such transient leaks are short-lived, rather than just
> reporting such objects as leaks, do another scan to confirm the
> suspected objects. If no new leaks are found during the first scan, skip
> the confirmation one.
>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> Assisted-by: Claude:claude-opus-4-8
> Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

Thanks for your patch!

For how long does this postpone the reporting of a real leak?
I am asking, because I have a few known leaks in my local tree,
and it already takes a while before they are reported.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds