Re: [syzbot] [cgroups?] possible deadlock in cgroup_free

[Oleg Nesterov]

On 11/19, Tejun Heo wrote:
>
> On Thu, Nov 16, 2023 at 05:25:05PM -0800, syzbot wrote:
> > syzbot has bisected this issue to:
> >
> > commit 2d25a889601d2fbc87ec79b30ea315820f874b78
> > Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > Date:   Sun Sep 17 11:24:21 2023 +0000
> >
> >     ptrace: Convert ptrace_attach() to use lock guards
>
> Looks like the tasklist_lock conversion in ptrace_attach() forgot _irq.
> Peter, Oleg?

Yes, please see

	Re: [syzbot] [kernel?] inconsistent lock state in ptrace_attach
	https://lore.kernel.org/all/20231117094531.GN8262@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/

Oleg.