From: Kees Cook <keescook@chromium.org>
To: John Stultz <john.stultz@linaro.org>, Laura Abbott <labbott@redhat.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
lkml <linux-kernel@vger.kernel.org>
Subject: Re: REGRESSION?: debugfs: inode: debugfs_create_dir uses mode permission from parent
Date: Tue, 12 Jun 2018 15:52:19 -0700 [thread overview]
Message-ID: <CAGXu5jJe5dy65OqmSUr6vdfsZJfoPHLH7z+Uuk3MRy+VQoSydA@mail.gmail.com> (raw)
In-Reply-To: <CALAqxLVCpyKzGJPVtBuipnZbGbDC_Z0rPBrn-J2mkMsQsSvdtA@mail.gmail.com>
On Tue, Jun 12, 2018 at 3:40 PM, John Stultz <john.stultz@linaro.org> 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
next prev parent reply other threads:[~2018-06-12 22:52 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-12 22:40 REGRESSION?: debugfs: inode: debugfs_create_dir uses mode permission from parent John Stultz
2018-06-12 22:52 ` Kees Cook [this message]
2018-06-12 22:53 ` John Stultz
2018-06-13 4:58 ` Greg Kroah-Hartman
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