From patchwork Wed Jun 19 13:19:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11004143 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 525A3112C for ; Wed, 19 Jun 2019 13:19:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 40DE626E1A for ; Wed, 19 Jun 2019 13:19:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3548E283BB; Wed, 19 Jun 2019 13:19:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CD50D26E1A for ; Wed, 19 Jun 2019 13:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730650AbfFSNTF (ORCPT ); Wed, 19 Jun 2019 09:19:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36432 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726518AbfFSNTF (ORCPT ); Wed, 19 Jun 2019 09:19:05 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7589819CF7A; Wed, 19 Jun 2019 13:19:03 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-57.rdu2.redhat.com [10.10.120.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 37F665DA5B; Wed, 19 Jun 2019 13:19:01 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 02/10] keys: sparse: Fix incorrect RCU accesses [ver #3] From: David Howells To: keyrings@vger.kernel.org, ebiggers@kernel.org Cc: James Morris , dhowells@redhat.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 19 Jun 2019 14:19:00 +0100 Message-ID: <156095034027.9363.14636937467673662369.stgit@warthog.procyon.org.uk> In-Reply-To: <156095032052.9363.8954337545422131435.stgit@warthog.procyon.org.uk> References: <156095032052.9363.8954337545422131435.stgit@warthog.procyon.org.uk> User-Agent: StGit/unknown-version MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 19 Jun 2019 13:19:05 +0000 (UTC) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Fix a pair of accesses that should be using RCU protection. rcu_dereference_protected() is needed to access task_struct::real_parent. current_cred() should be used to access current->cred. Signed-off-by: David Howells Reviewed-by: James Morris --- security/keys/keyctl.c | 3 ++- security/keys/request_key_auth.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index 3e4053a217c3..0f947bcbad46 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -1524,7 +1524,8 @@ long keyctl_session_to_parent(void) ret = -EPERM; oldwork = NULL; - parent = me->real_parent; + parent = rcu_dereference_protected(me->real_parent, + lockdep_is_held(&tasklist_lock)); /* the parent mustn't be init and mustn't be a kernel thread */ if (parent->pid <= 1 || !parent->mm) diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c index bda6201c6c45..572c7a60473a 100644 --- a/security/keys/request_key_auth.c +++ b/security/keys/request_key_auth.c @@ -152,7 +152,7 @@ struct key *request_key_auth_new(struct key *target, const char *op, struct key *dest_keyring) { struct request_key_auth *rka, *irka; - const struct cred *cred = current->cred; + const struct cred *cred = current_cred(); struct key *authkey = NULL; char desc[20]; int ret = -ENOMEM;