Re: [2.6 patch] net/sctp/socket.c: add missing sctp_spin_unlock_irqrestore

[Al Viro <viro@ftp.linux.org.uk>]

On Sun, Nov 26, 2006 at 06:00:53PM +0800, Eugene Teo wrote:
> This patch adds a missing sctp_spin_unlock_irqrestore when returning
> from "if(space_left<addrlen)" condition.
>                 if (copy_to_user(*to, &temp, addrlen)) {
> -                       sctp_spin_unlock_irqrestore(&sctp_local_addr_lock,
> -                                                   flags);
> -                       return -EFAULT;
> +                       err = -EFAULT;
> +                       goto unlock;

> +       sctp_spin_unlock_irqrestore(&sctp_local_addr_lock, flags);
> +       return err;
>  }

You do realize that it's obviously still badly broken, don't you?
copy_to_user() under a spinlock is a recipe for deadlock, especially
if you've got interrupts disabled...

I have a beginning of locking fixes in that shitpile, but it's incomplete
and bloody painful ;-/