Re: [PATCH 3/3] bpf: Make sure that ->comm does not change under us.

From: Richard Weinberger
Date: Mon Oct 16 2017 - 16:55:12 EST


Am Montag, 16. Oktober 2017, 22:50:43 CEST schrieb Daniel Borkmann:
> > struct task_struct *task = current;
> >
> > + task_lock(task);
> >
> > strncpy(buf, task->comm, size);
> >
> > + task_unlock(task);
>
> Wouldn't this potentially lead to a deadlock? E.g. you attach yourself
> to task_lock() / spin_lock() / etc, and then the BPF prog triggers the
> bpf_get_current_comm() taking the lock again ...

Yes, but doesn't the same apply to the use case when I attach to strncpy()
and run bpf_get_current_comm()?

Thanks,
//richard