linux-kernel - Re: [PATCH v3] ptrace: Fix fork event messages across pid namespaces

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: <CAF52+S4hs2oM_qw9Zo-6qiOp_-Cyt3ZpL+zU2_MUv=d7UKPqEA@mail.gmail.com>
Date:	Wed, 2 Apr 2014 15:37:33 -0700
From:	Matthew Dempsky <mdempsky@...omium.org>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	Kees Cook <keescook@...omium.org>,
	Julien Tinnes <jln@...omium.org>,
	Roland McGrath <mcgrathr@...omium.org>,
	Jan Kratochvil <jan.kratochvil@...hat.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3] ptrace: Fix fork event messages across pid namespaces

On Wed, Apr 2, 2014 at 2:58 PM, Matthew Dempsky <mdempsky@...gle.com> wrote:
> Otherwise, it looks like (e.g.) the attempts to get the parent's pid
> in fill_prstatus() and tomoyo_sys_getppid() are also theoretical races
> of the same kind?

Doh, nevermind, those functions would potentially be use null "struct
pid" pointers, not "struct pid_namespace" pointers; and pid_nr_ns()
guards against pid being null.

Okay, I think I understand now why guarding against the
task_parent_pid_ns() here is consistent with other RCU code.  I'll
send a revised patch that does that.

Also, it looks like "0" is the conventional value for unrepresentable
pid_t values, so I'll change to do that too.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/