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=-0.6 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIM_INVALID,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id 8E697C433EF for ; Tue, 12 Jun 2018 22:52:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEBD92089C for ; Tue, 12 Jun 2018 22:52:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="UJZB6uOp"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="mq8wFpoo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CEBD92089C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.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 S934876AbeFLWwW (ORCPT ); Tue, 12 Jun 2018 18:52:22 -0400 Received: from mail-yb0-f196.google.com ([209.85.213.196]:33927 "EHLO mail-yb0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934368AbeFLWwV (ORCPT ); Tue, 12 Jun 2018 18:52:21 -0400 Received: by mail-yb0-f196.google.com with SMTP id n23-v6so235379ybg.1 for ; Tue, 12 Jun 2018 15:52:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=gDNDBIenLbV8PGNVV8GjtgxrPeGVtRQFwPHBOMiPlMs=; b=UJZB6uOpfJU7LdOXb8zklhrtHyYi4QA4Syd6u+9PeImzEySLplGtVesMagb/y60UKA k7yFoj3zKz7mSERZhTgRCy92Nf8T1so9O90MULyVFsQOvsA92zpQ43J5Ny2CVoupaa/c cNB0CK+LFXAWVjBRCscaI9n6MTYp5tqRqnwieJDGJqZVG+RKFI5VfZZC7BKOKHMHowOx 5d+FLyigUr6zKHc9n6xhF1CMZBEDzUydcY3r1AIxorGvi/DCLTLm1Kjlqdc4D/bGx95h PnJ990ZBnNVOG0uZAyM43Xo0DEF277jovWiAZN7+xZNm2vyW47Qg8/lsYIdFrlN2H/gz lZZg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=gDNDBIenLbV8PGNVV8GjtgxrPeGVtRQFwPHBOMiPlMs=; b=mq8wFpooaIJQiWwKZX9yR/oXboPAxD2dDCLZ9MJEUHx2frB/t4eyzEECAQWt6P/OHU jAyCacScMpd2iEaJPbMjcJR7ZiGYwFQdpDr1FFEkQN1duo4carlZ/hJBB2M+kMMQ33V0 9e9S6PSpM1UZ7lCkAbnWZCaKQVdRovOv6Dl1k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=gDNDBIenLbV8PGNVV8GjtgxrPeGVtRQFwPHBOMiPlMs=; b=azccvYkoet85wdMJtl+u8BZjnRutAVRMoEUarNeSPa6F4jEcbT6nOyqqDUA1z/IbkF 442g06MALfVmOH4veS3VE53Ey0DcEy3+RydeR9RNjZQVRtR/2ZXHxmXiZUTpoznsRdZ6 Jdo7rgfTrBfvAiBF0MelIQc293QiBB0nD/TX9lfvlelvW9mwdgzgx+JCs2GRQqQU5Po4 lKVwl0VvaW2kPIymxfpXQKchmxDwuAR2Mb9qJasdfFzg4w6/NgHbyFbFeW36+YNRSubr nxrYkmoBnXdsrQ8YCZY/o/awUAvBKwVjaCu5r6DOTjeq5CbDv5//qacKudcQ3MqyjHiH M3zA== X-Gm-Message-State: APt69E198mJITEc4LQqRn8nyqruIupofL/Lvxvcnlaiwlcu2JHcTeAwH rG93JzqgVCuuLeLOwq7dxESNi8u2AQ6Z1vAqUg8V8A== X-Google-Smtp-Source: ADUXVKJ1ei6c81Gcd8blZ+vP+jpHo3nwF3e6F+/eFbUP73p33Rv4r2P50zHBTCPu1uuFvRtru1xKrucAo9JBOSkkv/4= X-Received: by 2002:a25:8b05:: with SMTP id i5-v6mr1232117ybl.484.1528843940454; Tue, 12 Jun 2018 15:52:20 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a25:d6c5:0:0:0:0:0 with HTTP; Tue, 12 Jun 2018 15:52:19 -0700 (PDT) In-Reply-To: References: From: Kees Cook Date: Tue, 12 Jun 2018 15:52:19 -0700 X-Google-Sender-Auth: fWDRJqH2C-3xXkYUwj44dRHO6VQ Message-ID: Subject: Re: REGRESSION?: debugfs: inode: debugfs_create_dir uses mode permission from parent To: John Stultz , Laura Abbott Cc: Thomas Richter , Greg Kroah-Hartman , lkml 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 Tue, Jun 12, 2018 at 3:40 PM, John Stultz wrote: > Hey all, > I noticed recently that linus/master (plus patches) stopped booting > to UI on HiKey960, and I bisected the issue down to: > 92170b62f1c1 ("debugfs: inode: debugfs_create_dir uses mode permission > from parent") > > On the HiKey960 board, we mount debugfs via: > mount debugfs /sys/kernel/debug /sys/kernel/debug mode=755 > > But since the change, it seems most of the nodes in /sys/kernel/debug > are: drwx------ > > Which ends up breaking the egl library, keeping it from loading. > > This seems to be the expected behavior of the patch, but I'm surprised > the mode override is now ignored. It seems like the potential fix here > would be to set the /sys/kernel/debug dir to 755 prior to mounting? Or > is there some other advised solution? This change has already be reverted from other people reporting the problem. Perhaps the root cause is the lack of propagation of the mode= value? -Kees -- Kees Cook Pixel Security