Re: [PATCH] csky/kprobe: reclaim insn_slot on kprobe unregistration

[Guo Ren]

On Thu, May 26, 2022 at 11:30 PM Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:
>
> On Wed, 25 May 2022 16:02:41 +0800
> Liao Chang <liaochang1@xxxxxxxxxx> wrote:
>
> > On kprobe registration kernel allocate one insn_slot for new kprobe,
> > but it forget to reclaim the insn_slot on unregistration, leading to a
> > potential leakage.
> >
> > Reported-by: Chen Guokai <chenguokai17@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Liao Chang <liaochang1@xxxxxxxxxx>
>
> This looks good to me too. I think this should go through csky tree.
Okay, I would add the Fix line and put it into Linux-5.19-rc2.

>
> Reviewed-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
>
> Thank you,
>
>
> > ---
> >  arch/csky/kernel/probes/kprobes.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kprobes.c
> > index 42920f25e73c..661da54b418f 100644
> > --- a/arch/csky/kernel/probes/kprobes.c
> > +++ b/arch/csky/kernel/probes/kprobes.c
> > @@ -124,6 +124,10 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
> >
> >  void __kprobes arch_remove_kprobe(struct kprobe *p)
> >  {
> > +     if (p->ainsn.api.insn) {
> > +             free_insn_slot(p->ainsn.api.insn, 0);
> > +             p->ainsn.api.insn = NULL;
> > +     }
> >  }
> >
> >  static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
> > --
> > 2.17.1
> >
>
>
> --
> Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/