From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Subject: Re: [PATCH 15/24] asus-wmi: Restrict debugfs interface when the kernel is locked down Date: Fri, 07 Apr 2017 13:50:49 +0100 Message-ID: <31421.1491569449@warthog.procyon.org.uk> References: <149142326734.5101.4596394505987813763.stgit@warthog.procyon.org.uk> <149142340198.5101.8171352010918423590.stgit@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: Content-ID: <31420.1491569449.1@warthog.procyon.org.uk> Sender: owner-linux-security-module@vger.kernel.org To: Andy Shevchenko Cc: dhowells@redhat.com, "linux-kernel@vger.kernel.org" , matthew.garrett@nebula.com, linux-efi@vger.kernel.org, One Thousand Gnomes , Greg Kroah-Hartman , acpi4asus-user , Platform Driver , linux-security-module , keyrings@vger.kernel.org List-Id: platform-driver-x86.vger.kernel.org Andy Shevchenko wrote: > > From: Matthew Garrett > > > > We have no way of validating what all of the Asus WMI methods do on a given > > machine - and there's a risk that some will allow hardware state to be > > manipulated in such a way that arbitrary code can be executed in the > > kernel, circumventing module loading restrictions. Prevent that if the > > kernel is locked down. > > > + if (kernel_is_locked_down()) > > + return -EPERM; > > It looks a bit fragile when responsility of whatever reasons kernel > can't serve become a driver burden. > Can we fix this in debugfs framework instead? Fix it with debugfs how? We can't offload the decision to userspace. David