linux-kernel - Re: [PATCH 1/1] cred: copy_process() should clear child->replacement_session

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] [day] [month] [year] [list]

Date:	Wed, 11 Apr 2012 11:47:49 +0100
From:	David Howells <dhowells@...hat.com>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	dhowells@...hat.com,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH 1/1] cred: copy_process() should clear child->replacement_session_keyring

Oleg Nesterov <oleg@...hat.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@...r.kernel.org>
> Signed-off-by: Oleg Nesterov <oleg@...hat.com>

Acked-by: David Howells <dhowells@...hat.com>
--
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/