linux-kernel - Re: [PATCH 14/20] exit/syscall_user_dispatch: Send ordinary signals on failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <202110210940.3BBA18AA@keescook>
Date:   Thu, 21 Oct 2021 09:40:53 -0700
From:   Kees Cook <keescook@...omium.org>
To:     "Eric W. Biederman" <ebiederm@...ssion.com>
Cc:     linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Oleg Nesterov <oleg@...hat.com>,
        Al Viro <viro@...iv.linux.org.uk>,
        Gabriel Krisman Bertazi <krisman@...labora.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>
Subject: Re: [PATCH 14/20] exit/syscall_user_dispatch: Send ordinary signals
 on failure

On Thu, Oct 21, 2021 at 11:37:23AM -0500, Eric W. Biederman wrote:
> Kees Cook <keescook@...omium.org> writes:
> 
> > On Wed, Oct 20, 2021 at 12:44:00PM -0500, Eric W. Biederman wrote:
> >> Use force_fatal_sig instead of calling do_exit directly.  This ensures
> >> the ordinary signal handling path gets invoked, core dumps as
> >> appropriate get created, and for multi-threaded processes all of the
> >> threads are terminated not just a single thread.
> >
> > Yeah, looks good. Should be no visible behavior change.
> 
> It is observable in that an entire multi-threaded process gets
> terminated instead of a single thread.  But since these events should
> be handling of extra-ordinary events I don't expect there is anyone
> who wants to have a thread of their process survive.

Right -- sorry, I should have said that more clearly: "Besides the
single thread death now taking the whole process, there's not behavior
change (i.e. the signal delivery)." Still looks good to me.

-- 
Kees Cook