From: Oleg Nesterov <oleg@redhat.com>
To: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
akpm@linux-foundation.org
Subject: Re: [PATCH] kernel/kmod: fix use-after-free of the sub_infostructure
Date: Fri, 17 Oct 2014 17:21:56 +0200 [thread overview]
Message-ID: <20141017152156.GA6519@redhat.com> (raw)
In-Reply-To: <20141017093653.6fa60dff@mschwide>
On 10/17, Martin Schwidefsky wrote:
>
> On Thu, 16 Oct 2014 23:58:34 +0200
> Oleg Nesterov <oleg@redhat.com> wrote:
>
> > I also agree that the changelog could mention exec_mmap. Plus a comment
> > about UMH_NO_WAIT && sub_info->complete == NULL. So yes, perhaps v2 makes
> > sense if Martin agrees.
>
> Version 2 of the patch.
Thanks!
> All change requests have gone in except for the
> mention of exec_mmap. I don't quite get the relevance of it, do_execve
> can fail for the various reasons.
Yes. But if it fails before exec_mmap() (which in particular calls
mm_release()->complete_vfork_done()) we are safe; sub_info can't go away
because the parent sleeps in sys_wait4() if UMH_WAIT_PROC, or it sleeps
in wait_for_vfork_done() otherwise.
But this is minor, and this only relates to the changelog. So still/again
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
next prev parent reply other threads:[~2014-10-17 15:25 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-16 14:00 [PATCH] kernel/kmod: fix use-after-free of the sub_info structure Martin Schwidefsky
2014-10-16 16:57 ` Tetsuo Handa
2014-10-16 17:42 ` Oleg Nesterov
2014-10-16 21:30 ` [PATCH] kernel/kmod: fix use-after-free of the sub_infostructure Tetsuo Handa
2014-10-16 21:58 ` Oleg Nesterov
2014-10-17 7:04 ` Martin Schwidefsky
2014-10-17 7:36 ` Martin Schwidefsky
2014-10-17 12:55 ` [PATCH] kernel/kmod: fix use-after-free of the sub_info structure Tetsuo Handa
2014-10-17 15:21 ` Oleg Nesterov [this message]
2014-10-17 19:15 ` [PATCH 0/2] (Was: kernel/kmod: fix use-after-free of the sub_infostructure) Oleg Nesterov
2014-10-17 19:16 ` [PATCH 1/2] usermodehelper: don't use CLONE_VFORK for ____call_usermodehelper() Oleg Nesterov
2014-10-17 19:16 ` [PATCH 2/2] usermodehelper: kill the kmod_thread_locker logic Oleg Nesterov
2014-10-17 23:54 ` [PATCH 0/2] (Was: kernel/kmod: fix use-after-free of thesub_infostructure) Tetsuo Handa
2014-10-17 7:02 ` [PATCH] kernel/kmod: fix use-after-free of the sub_infostructure Martin Schwidefsky
2014-10-16 17:37 ` [PATCH] kernel/kmod: fix use-after-free of the sub_info structure Oleg Nesterov
2014-10-16 20:16 ` Oleg Nesterov
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