Re: [PATCH mm] fix for "kasan, fork: reset pointer tags of vmapped stacks"

[Andrey Konovalov]

On Wed, Feb 16, 2022 at 10:59 AM Marco Elver <elver@xxxxxxxxxx> wrote:
>
> On Tue, 15 Feb 2022 at 17:52, <andrey.konovalov@xxxxxxxxx> wrote:
> >
> > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> >
> > That patch didn't update the case when a stack is retrived from
> > cached_stacks in alloc_thread_stack_node(). As cached_stacks stores
> > vm_structs and not stack pointers themselves, the pointer tag needs
> > to be reset there as well.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
>
> Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
>
> Did the test catch this? If not, can this be tested?

Kind of, the kernel crashes on boot. I got KASAN_STACK accidentally
disabled in my SW_TAGS config, so I didn't see the crash until now.