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=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 C9FA9C282CD for ; Mon, 28 Jan 2019 15:58:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9662221916 for ; Mon, 28 Jan 2019 15:58:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691129; bh=y0pcngCZzwrcxRxKcORiJbXxdKye5RZUbzNlrSSyWDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=LHk7sZyaHRoo99mjSZUr9UdVx8hEtDfERu2Vc7pNBtyHph7DTiuoHYGWg6oCLZzPs u/Is1EqudISiW7sFH5/34+ucKruCBy8QuAFwoPlLaCFi0arSPkPb25qhTLdm9XDriO 7bjQmvU5uXZ7m9Qe2RRaIggqEgyrnGAxNgwj/0T4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730485AbfA1P6s (ORCPT ); Mon, 28 Jan 2019 10:58:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:44160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730466AbfA1P6q (ORCPT ); Mon, 28 Jan 2019 10:58:46 -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 1468321852; Mon, 28 Jan 2019 15:58:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691125; bh=y0pcngCZzwrcxRxKcORiJbXxdKye5RZUbzNlrSSyWDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CfY+K5hlG/51fmiXvI5sOQyzeGh3oCEMNS3f/DNtRd3r4N+NbqBbvIhov2ogesLEh PT+pv55aM2lkzrfupjvMcAvcVNoRAmu5dzYG4rt5elHEzDZy0LFbVW+Q5OPqejjvlP 1BhpufAnue6b72ySXxSgzZejuKR8RoEgyPxJ3Abg= 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 4.20 296/304] fs/proc/base.c: use ns_capable instead of capable for timerslack_ns Date: Mon, 28 Jan 2019 10:43:33 -0500 Message-Id: <20190128154341.47195-296-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128154341.47195-1-sashal@kernel.org> References: <20190128154341.47195-1-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 ce3465479447..98525af0953e 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