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,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 35A44C282C8 for ; Mon, 28 Jan 2019 16:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 01E042082C for ; Mon, 28 Jan 2019 16:41:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548693700; bh=jYmlpZDzwro/F6EmfSud0gR4DJHQLc7HMP53JSW4liU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XxS2u5tAjHg962XZM8bNjXhYh2N23nRCZM8hUMfnAK/x7PUHoPyX7RHN9gmAyxCSw UzgGShxU2ADRo4ls9RP9j8KQ7qTF7zQOd+vbylNbxAlVsAR9LJwAszFV9vML8Vb1zH vk7V+6kbaiUM7yKd+M27e28eAibKFsu2CsT+w/p8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389772AbfA1Qli (ORCPT ); Mon, 28 Jan 2019 11:41:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:60264 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389553AbfA1QXy (ORCPT ); Mon, 28 Jan 2019 11:23:54 -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 E97942147A; Mon, 28 Jan 2019 16:23:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548692633; bh=jYmlpZDzwro/F6EmfSud0gR4DJHQLc7HMP53JSW4liU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vlCxMpCDDOsvqbDTbhY8FU+xNV8WIrx7mKFYp4bwMvtycaA0dYExRaojAonmCXsCs 1WJZjZOpbhiCkYvi61V8T8KIltleobrKyzKpEV4zAYwgPgqx5yBi5e2Qz6LJex1piK V3YwWxP6R3VXNadsX8twvRapPVwmEytCDbhlPJnY= 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 4.9 103/107] fs/proc/base.c: use ns_capable instead of capable for timerslack_ns Date: Mon, 28 Jan 2019 11:19:43 -0500 Message-Id: <20190128161947.57405-103-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128161947.57405-1-sashal@kernel.org> References: <20190128161947.57405-1-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 79702d405ba7..f73de326c630 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2337,10 +2337,13 @@ 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) { @@ -2373,11 +2376,14 @@ 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