From: David Howells <dhowells@redhat.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: dhowells@redhat.com,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH 1/1] cred: copy_process() should clear child->replacement_session_keyring
Date: Wed, 11 Apr 2012 11:47:49 +0100 [thread overview]
Message-ID: <14057.1334141269@redhat.com> (raw)
In-Reply-To: <20120409190350.GA14716@redhat.com>
Oleg Nesterov <oleg@redhat.com> wrote:
> keyctl_session_to_parent(task) sets ->replacement_session_keyring,
> it should be processed and cleared by key_replace_session_keyring().
>
> However, this task can fork before it notices TIF_NOTIFY_RESUME and
> the new child gets the bogus ->replacement_session_keyring copied by
> dup_task_struct(). This is obviously wrong and, if nothing else, this
> leads to put_cred(already_freed_cred).
>
> change copy_creds() to clear this member. If copy_process() fails
> before this point the wrong ->replacement_session_keyring doesn't
> matter, exit_creds() won't be called.
>
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
prev parent reply other threads:[~2012-04-11 10:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-09 19:03 [PATCH 0/1] cred: copy_process() should clear child->replacement_session_keyring Oleg Nesterov
2012-04-09 19:03 ` [PATCH 1/1] " Oleg Nesterov
2012-04-10 1:05 ` [RFC PATCH 0/1] task_work_queue: add generic process-context callbacks Oleg Nesterov
2012-04-10 1:06 ` [RFC PATCH 1/1] " Oleg Nesterov
2012-04-11 10:47 ` David Howells [this message]
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