From: Oleg Nesterov <oleg@redhat.com>
To: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Subject: Re: [PATCH] kernel/kmod: fix use-after-free of the sub_info structure
Date: Thu, 16 Oct 2014 22:16:20 +0200 [thread overview]
Message-ID: <20141016201620.GA25225@redhat.com> (raw)
In-Reply-To: <20141016173733.GA18318@redhat.com>
On 10/16, Oleg Nesterov wrote:
>
> OK... I am wondering if __call_usermodehelper() still needs CLONE_VFORK
> with this patch.
Yes, looks like it doesn't, but this needs another patch.
> > @@ -588,7 +580,7 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait)
> > goto out;
> > }
> >
> > - sub_info->complete = &done;
> > + sub_info->complete = (wait == UMH_NO_WAIT) ? NULL : &done;
>
> This probably needs a comment, and the comment in umh_complete() should
> be updated,
>
> - we own sub_info, the UMH_KILLABLE caller has gone away.
> + we own sub_info, the UMH_KILLABLE caller has gone away
> + or the caller used UMH_NO_WAIT.
>
> The patch looks correct at first glance. I'll try to re-read it later
> once again.
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
prev parent reply other threads:[~2014-10-16 20:19 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 ` [PATCH] kernel/kmod: fix use-after-free of the sub_infostructure Oleg Nesterov
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 [this message]
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