From patchwork Mon Oct 18 17:23:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 12567479 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 B8BE1C433EF for ; Mon, 18 Oct 2021 17:23:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5B4E86103B for ; Mon, 18 Oct 2021 17:23:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5B4E86103B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id F3ACD940007; Mon, 18 Oct 2021 13:23:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EE88A900002; Mon, 18 Oct 2021 13:23:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DD852940007; Mon, 18 Oct 2021 13:23:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0144.hostedemail.com [216.40.44.144]) by kanga.kvack.org (Postfix) with ESMTP id D059F900002 for ; Mon, 18 Oct 2021 13:23:48 -0400 (EDT) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 900AF18024AEE for ; Mon, 18 Oct 2021 17:23:48 +0000 (UTC) X-FDA: 78710230536.05.3A1CF9E Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by imf01.hostedemail.com (Postfix) with ESMTP id BB3975082D7A for ; Mon, 18 Oct 2021 17:23:44 +0000 (UTC) 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 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) X-Stat-Signature: m9feysii7mkwi81zx8169s8iwd4z3bmq Authentication-Results: imf01.hostedemail.com; dkim=none; spf=pass (imf01.hostedemail.com: domain of ebiederm@xmission.com designates 166.70.13.232 as permitted sender) smtp.mailfrom=ebiederm@xmission.com; dmarc=pass (policy=none) header.from=xmission.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: BB3975082D7A X-HE-Tag: 1634577824-392538 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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);