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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 ADF3EC282CE for ; Mon, 11 Feb 2019 14:50:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EC6B20844 for ; Mon, 11 Feb 2019 14:50:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549896611; bh=n6S1hpzcezJSRZDPSXdItOB3/W4X91OZZ8V/hck5Sq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MeALzYusjkDjPR7PD8YRf1ebgSNxG1nUGPAY9fdUGJTBGE5xPwg5asX9G05cmyAwl fwYwEz29vEpK4DFCk9IwQ3J2XhRwePgpFRmHhWuvv79aAFFtRvIimzFO3FKo8Kjm8R 2dL0vW7HLw8fUkdSvUbXFGFCynO3Nh6eYLVOBaFI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388033AbfBKOuK (ORCPT ); Mon, 11 Feb 2019 09:50:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:35846 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733283AbfBKOuI (ORCPT ); Mon, 11 Feb 2019 09:50:08 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 785B82081B; Mon, 11 Feb 2019 14:50:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549896607; bh=n6S1hpzcezJSRZDPSXdItOB3/W4X91OZZ8V/hck5Sq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Lbbd6Lb17cIzTBDICDAhrRSFCvEd/YusJypgcmEK+iO+j1fFBjutnQCShjC6sGlEo Rizd9PfAQo8PjINuc/XW1J/FNHtiOAiz+BfF5vDhv2CTQmsJ0Vtj38pzR2YcLj7Woq MkZJgnzX8FXcOrFT8lvfbMS6j7SWyMkAJPBE4Eio= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin Gordon , "Eric W. Biederman" , John Stultz , 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 Subject: [PATCH 4.19 240/313] fs/proc/base.c: use ns_capable instead of capable for timerslack_ns Date: Mon, 11 Feb 2019 15:18:40 +0100 Message-Id: <20190211141909.457022324@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141852.749630980@linuxfoundation.org> References: <20190211141852.749630980@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ [ 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