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 X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 545CBC282C8 for ; Mon, 28 Jan 2019 16:11:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2172C21848 for ; Mon, 28 Jan 2019 16:11:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691901; bh=LyYWqI/kO+VSj4t6CstNgqygIq9zztZV3LFIAJYf4vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=X8zUPyLfCw4CSJH4vyHlsPxbLNw10oEHTFJ6nY8Zqpoxisru7QCkF3C0V3gTcHEF3 qDNz10rhAz25qbsZIFcP+r3mPxyr0FZ26UmvjmWxrMChqNehEazQKVrGaFybWVdKay /6Ahf32cZpEUWAOof9ci4uUyqbWSl9XwvyWoxh8A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733000AbfA1QLj (ORCPT ); Mon, 28 Jan 2019 11:11:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:38744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732971AbfA1QLg (ORCPT ); Mon, 28 Jan 2019 11:11:36 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 072082175B; Mon, 28 Jan 2019 16:11:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691895; bh=LyYWqI/kO+VSj4t6CstNgqygIq9zztZV3LFIAJYf4vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LvCZTBDybkz9mojIxaYk5iatBy0XYkcZq/CTMwP58Np8lOS7v+kYJJENMJep6uv4+ mPO1DGny5L/GkFPWpGMJFd5ozqr9ZGMqZCxlrWsCWvI7NXBvoeew0THdghsARF7A1M MW8sNfkB7cu/OWrQMpK65ckHdgb2mY9460dyrLR8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Benjamin Gordon , John Stultz , "Eric W. Biederman" , Kees Cook , "Serge E. Hallyn" , Thomas Gleixner , Arjan van de Ven , Oren Laadan , Ruchi Kandoi , Rom Lemarchand , Todd Kjos , Colin Cross , Nick Kralevich , Dmitry Shmidt , Elliott Hughes , Alexey Dobriyan , Andrew Morton , Linus Torvalds , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 251/258] fs/proc/base.c: use ns_capable instead of capable for timerslack_ns Date: Mon, 28 Jan 2019 10:59:17 -0500 Message-Id: <20190128155924.51521-251-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128155924.51521-1-sashal@kernel.org> References: <20190128155924.51521-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Benjamin Gordon [ Upstream commit 8da0b4f692c6d90b09c91f271517db746a22ff67 ] Access to timerslack_ns is controlled by a process having CAP_SYS_NICE in its effective capability set, but the current check looks in the root namespace instead of the process' user namespace. Since a process is allowed to do other activities controlled by CAP_SYS_NICE inside a namespace, it should also be able to adjust timerslack_ns. Link: http://lkml.kernel.org/r/20181030180012.232896-1-bmgordon@google.com Signed-off-by: Benjamin Gordon Acked-by: "Eric W. Biederman" Cc: John Stultz Cc: "Eric W. Biederman" Cc: Kees Cook Cc: "Serge E. Hallyn" Cc: Thomas Gleixner Cc: Arjan van de Ven Cc: Oren Laadan Cc: Ruchi Kandoi Cc: Rom Lemarchand Cc: Todd Kjos Cc: Colin Cross Cc: Nick Kralevich Cc: Dmitry Shmidt Cc: Elliott Hughes Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/proc/base.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 7e9f07bf260d..5bdcf2159ff0 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2356,10 +2356,13 @@ static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, return -ESRCH; if (p != current) { - if (!capable(CAP_SYS_NICE)) { + rcu_read_lock(); + if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { + rcu_read_unlock(); count = -EPERM; goto out; } + rcu_read_unlock(); err = security_task_setscheduler(p); if (err) { @@ -2392,11 +2395,14 @@ static int timerslack_ns_show(struct seq_file *m, void *v) return -ESRCH; if (p != current) { - - if (!capable(CAP_SYS_NICE)) { + rcu_read_lock(); + if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { + rcu_read_unlock(); err = -EPERM; goto out; } + rcu_read_unlock(); + err = security_task_getscheduler(p); if (err) goto out; -- 2.19.1