From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C39EC433FE for ; Mon, 18 Oct 2021 17:23:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A7A660241 for ; Mon, 18 Oct 2021 17:23:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234062AbhJRR0A (ORCPT ); Mon, 18 Oct 2021 13:26:00 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:46070 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233099AbhJRRZ6 (ORCPT ); Mon, 18 Oct 2021 13:25:58 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]:51982) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mcWMV-00A8a6-4c; Mon, 18 Oct 2021 11:23:47 -0600 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95]:46216 helo=email.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1mcWMU-0045zF-90; Mon, 18 Oct 2021 11:23:46 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Alexey Gladkov Cc: Rune Kleveland , Yu Zhao , Jordan Glover , LKML , linux-mm@kvack.org, containers@lists.linux-foundation.org, Hillf Danton , David Howells , Jarkko Sakkinen References: <1M9_d6wrcu6rdPe1ON0_k0lOxJMyyot3KAb1gdyuwzDPC777XVUWPHoTCEVmcK3fYfgu7sIo3PSaLe9KulUdm4TWVuqlbKyYGxRAjsf_Cpk=@protonmail.ch> <87ee9pa6xw.fsf@disp2133> <878rzw77i3.fsf@disp2133> <20210929173611.fo5traia77o63gpw@example.org> <20210930130640.wudkpmn3cmah2cjz@example.org> <878rz8wwb6.fsf@disp2133> <87v92cvhbf.fsf@disp2133> <87mtnavszx.fsf_-_@disp2133> <87fssytizw.fsf_-_@disp2133> <871r4itfjw.fsf_-_@disp2133> Date: Mon, 18 Oct 2021 12:23:39 -0500 In-Reply-To: <871r4itfjw.fsf_-_@disp2133> (Eric W. Biederman's message of "Mon, 18 Oct 2021 12:21:07 -0500") Message-ID: <87pms2s0v8.fsf_-_@disp2133> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1mcWMU-0045zF-90;;;mid=<87pms2s0v8.fsf_-_@disp2133>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1/V1ZFMdVPsJ2CxIQJt/vIa0Zcg4nDjRmY= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH 2/3] ucounts: Proper error handling in set_cred_ucounts X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Instead of leaking the ucounts in new if alloc_ucounts fails, store the result of alloc_ucounts into a temporary variable, which is later assigned to new->ucounts. Cc: stable@vger.kernel.org Fixes: 905ae01c4ae2 ("Add a reference to ucounts for each cred") Signed-off-by: "Eric W. Biederman" --- kernel/cred.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/cred.c b/kernel/cred.c index 3d163bfd64a9..16c05dfbec4d 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -669,7 +669,7 @@ int set_cred_ucounts(struct cred *new) { struct task_struct *task = current; const struct cred *old = task->real_cred; - struct ucounts *old_ucounts = new->ucounts; + struct ucounts *new_ucounts, *old_ucounts = new->ucounts; if (new->user == old->user && new->user_ns == old->user_ns) return 0; @@ -681,9 +681,10 @@ int set_cred_ucounts(struct cred *new) if (old_ucounts && old_ucounts->ns == new->user_ns && uid_eq(old_ucounts->uid, new->euid)) return 0; - if (!(new->ucounts = alloc_ucounts(new->user_ns, new->euid))) + if (!(new_ucounts = alloc_ucounts(new->user_ns, new->euid))) return -EAGAIN; + new->ucounts = new_ucounts; if (old_ucounts) put_ucounts(old_ucounts); -- 2.20.1