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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 B2244ECDE46 for ; Thu, 25 Oct 2018 17:20:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68DBC2083E for ; Thu, 25 Oct 2018 17:20:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linaro.org header.i=@linaro.org header.b="D2R7sD3j" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68DBC2083E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728045AbeJZByC (ORCPT ); Thu, 25 Oct 2018 21:54:02 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:44950 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727401AbeJZByC (ORCPT ); Thu, 25 Oct 2018 21:54:02 -0400 Received: by mail-wr1-f66.google.com with SMTP id q6-v6so10132563wrw.11 for ; Thu, 25 Oct 2018 10:20:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=1bJs3q1wp8WqpHBYXRCtRsUapjWa79UF45pDkektjFM=; b=D2R7sD3j91f2Ca5iUU4T8nVOL5FlvnHfzOcMpW8Bjrm3nF7iPO6x+2TMGukTXawDKR Xq4JsJdjHhjFInDFcNlJg/15npPZeIsR2lOw0JjD1OY/Hp28TuCMOSrbTeQ5fHRnyLi8 2zO3SKxWPxY+x1PJ18DjtNXRH9QhyChQBr4A0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=1bJs3q1wp8WqpHBYXRCtRsUapjWa79UF45pDkektjFM=; b=HC+Wxf5iKpxi8Axqq4rHElWkiM63ITaYJzjQzFzEyL9XkqwRUraWvAu/astn5EbkBP lwhoZUPV9583xJKG/0t4boj66o48NLBJ+y/Rex+EMkhjYZcNzs07CaNzlLm8wr0muf/r db/CZAsSjUUmSw/r477iErppZjZyyonRGpZFySctC++mqQxNRUfSmCncCXxB2MRaCMwx mN6Z4/W2K8vnzqVrJICM5C5G7YBV4uTXm+io7iq0Pi/DRSWDiW76kHn1zAuN8WrMO8bm RwMDkQaJUWp9hjbgvuEnN3IJFymhj/JRDat/wgpkjgrDl0ZQ8u18VAE/VxggdRERWVRB G88g== X-Gm-Message-State: AGRZ1gJABtlZZS9RT8GkSMPrl5zCio4nG+3tEJBOKDOAM+U+h6gq1kWb 9aPpZz2/ENXxaDkj9jCb29nj/lcFX5IIbtWgPK4xDw== X-Google-Smtp-Source: AJdET5dfBHPB5FPqT5RvRWYd3NGWr1FOe6jvPdBb9cS9JzXGAFpA3lH7CRBBbP4TXniCzevm2K1k8rBKq8M/8qFOjCY= X-Received: by 2002:a5d:4f0d:: with SMTP id c13-v6mr2790323wru.50.1540488019347; Thu, 25 Oct 2018 10:20:19 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a1c:4054:0:0:0:0:0 with HTTP; Thu, 25 Oct 2018 10:20:18 -0700 (PDT) In-Reply-To: <20181017224738.193598-1-bmgordon@google.com> References: <20181017224738.193598-1-bmgordon@google.com> From: John Stultz Date: Thu, 25 Oct 2018 10:20:18 -0700 Message-ID: Subject: Re: [PATCH] proc: use ns_capable instead of capable for timerslack_ns To: bmgordon@google.com Cc: lkml , 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 , Android Kernel Team , Andrew Morton Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 17, 2018 at 3:47 PM, wrote: > From: Benjamin Gordon > > 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. > > Signed-off-by: Benjamin Gordon > Cc: John Stultz > 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: Android Kernel Team > Cc: Andrew Morton > --- > fs/proc/base.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/proc/base.c b/fs/proc/base.c > index 7e9f07bf260d..4b50937dff80 100644 > --- a/fs/proc/base.c > +++ b/fs/proc/base.c > @@ -2356,7 +2356,7 @@ static ssize_t timerslack_ns_write(struct file *file, const char __user *buf, > return -ESRCH; > > if (p != current) { > - if (!capable(CAP_SYS_NICE)) { > + if (!ns_capable(file->f_cred->user_ns, CAP_SYS_NICE)) { > count = -EPERM; > goto out; > } > @@ -2393,7 +2393,7 @@ static int timerslack_ns_show(struct seq_file *m, void *v) > > if (p != current) { > > - if (!capable(CAP_SYS_NICE)) { > + if (!ns_capable(seq_user_ns(m), CAP_SYS_NICE)) { > err = -EPERM; > goto out; > } Looks reasonable to me. Acked-by: John Stultz thanks -john