From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758541Ab2JAXY1 (ORCPT ); Mon, 1 Oct 2012 19:24:27 -0400 Received: from 1wt.eu ([62.212.114.60]:35328 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932871Ab2JAXBR (ORCPT ); Mon, 1 Oct 2012 19:01:17 -0400 Message-Id: <20121001225159.902084886@1wt.eu> User-Agent: quilt/0.48-1 Date: Tue, 02 Oct 2012 00:52:51 +0200 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Oleg Nesterov , David Howells , Linus Torvalds , Willy Tarreau Subject: [ 054/180] cred: copy_process() should clear child->replacement_session_keyring In-Reply-To: <6a854f579a99b4fe2efaca1057e8ae22@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit 79549c6dfda0603dba9a70a53467ce62d9335c33 upstream 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: Signed-off-by: Oleg Nesterov Acked-by: David Howells Signed-off-by: Linus Torvalds Signed-off-by: Willy Tarreau --- kernel/cred.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/cred.c b/kernel/cred.c index 0b5b5fc..9c06d10 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -443,6 +443,8 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) mutex_init(&p->cred_guard_mutex); + p->replacement_session_keyring = NULL; + if ( #ifdef CONFIG_KEYS !p->cred->thread_keyring && -- 1.7.2.1.45.g54fbc