Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-27 Thread Greg KH
On Wed, Mar 27, 2019 at 10:39:53AM -0700, Andy Lutomirski wrote: > On Tue, Mar 26, 2019 at 10:33 PM Greg KH wrote: > > > > On Tue, Mar 26, 2019 at 10:29:41PM -0700, Andy Lutomirski wrote: > > > > > > > > > > On Mar 26, 2019, at 10:06 PM, Greg KH > > > > wrote: > > > > > > > >> On Tue, Mar 26,

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-27 Thread Greg KH
On Wed, Mar 27, 2019 at 10:42:18AM -0700, Matthew Garrett wrote: > On Wed, Mar 27, 2019 at 10:40 AM Andy Lutomirski wrote: > > As far as I'm concerned, preventing root from crashing the system > > should not be a design goal of lockdown at all. And I think that the > > "integrity" mode should be

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-27 Thread Matthew Garrett
On Wed, Mar 27, 2019 at 10:40 AM Andy Lutomirski wrote: > As far as I'm concerned, preventing root from crashing the system > should not be a design goal of lockdown at all. And I think that the > "integrity" mode should be as non-annoying as possible, so I think we > should allow reading from

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-27 Thread Andy Lutomirski
On Tue, Mar 26, 2019 at 10:33 PM Greg KH wrote: > > On Tue, Mar 26, 2019 at 10:29:41PM -0700, Andy Lutomirski wrote: > > > > > > > On Mar 26, 2019, at 10:06 PM, Greg KH wrote: > > > > > >> On Tue, Mar 26, 2019 at 09:29:14PM -0700, Andy Lutomirski wrote: > > >>> On Tue, Mar 26, 2019 at 5:31 PM

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-27 Thread James Morris
On Wed, 27 Mar 2019, Greg KH wrote: > Personally, I think these are all just "confidentiality" type things, > but who really knows given the wild-west nature of debugfs (which is as > designed). And given that I think this patch series just crazy anyway, > I really don't care :) Why do you

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Greg KH
On Tue, Mar 26, 2019 at 10:29:41PM -0700, Andy Lutomirski wrote: > > > > On Mar 26, 2019, at 10:06 PM, Greg KH wrote: > > > >> On Tue, Mar 26, 2019 at 09:29:14PM -0700, Andy Lutomirski wrote: > >>> On Tue, Mar 26, 2019 at 5:31 PM Greg KH > >>> wrote: > >>> > On Tue, Mar 26, 2019 at

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Andy Lutomirski
> On Mar 26, 2019, at 10:06 PM, Greg KH wrote: > >> On Tue, Mar 26, 2019 at 09:29:14PM -0700, Andy Lutomirski wrote: >>> On Tue, Mar 26, 2019 at 5:31 PM Greg KH wrote: >>> On Tue, Mar 26, 2019 at 12:20:24PM -0700, Andy Lutomirski wrote: On Tue, Mar 26, 2019 at 11:28 AM Matthew

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Greg KH
On Tue, Mar 26, 2019 at 09:29:14PM -0700, Andy Lutomirski wrote: > On Tue, Mar 26, 2019 at 5:31 PM Greg KH wrote: > > > > On Tue, Mar 26, 2019 at 12:20:24PM -0700, Andy Lutomirski wrote: > > > On Tue, Mar 26, 2019 at 11:28 AM Matthew Garrett > > > wrote: > > > > > > > > From: Matthew Garrett >

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Andy Lutomirski
On Tue, Mar 26, 2019 at 5:31 PM Greg KH wrote: > > On Tue, Mar 26, 2019 at 12:20:24PM -0700, Andy Lutomirski wrote: > > On Tue, Mar 26, 2019 at 11:28 AM Matthew Garrett > > wrote: > > > > > > From: Matthew Garrett > > > > > > debugfs has not been meaningfully audited in terms of ensuring that >

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Greg KH
On Tue, Mar 26, 2019 at 07:06:36PM -0700, Matthew Garrett wrote: > On Tue, Mar 26, 2019 at 5:31 PM Greg KH wrote: > > On Tue, Mar 26, 2019 at 11:27:41AM -0700, Matthew Garrett wrote: > > > From: Matthew Garrett > > > > > > debugfs has not been meaningfully audited in terms of ensuring that > > >

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Matthew Garrett
On Tue, Mar 26, 2019 at 5:31 PM Greg KH wrote: > On Tue, Mar 26, 2019 at 11:27:41AM -0700, Matthew Garrett wrote: > > From: Matthew Garrett > > > > debugfs has not been meaningfully audited in terms of ensuring that > > userland cannot trample over the kernel. At Greg's request, disable > >

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Greg KH
On Tue, Mar 26, 2019 at 11:27:41AM -0700, Matthew Garrett wrote: > From: Matthew Garrett > > debugfs has not been meaningfully audited in terms of ensuring that > userland cannot trample over the kernel. At Greg's request, disable > access to it entirely when the kernel is locked down. This is

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Greg KH
On Tue, Mar 26, 2019 at 12:20:24PM -0700, Andy Lutomirski wrote: > On Tue, Mar 26, 2019 at 11:28 AM Matthew Garrett > wrote: > > > > From: Matthew Garrett > > > > debugfs has not been meaningfully audited in terms of ensuring that > > userland cannot trample over the kernel. At Greg's request,

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Matthew Garrett
On Tue, Mar 26, 2019 at 12:20 PM Andy Lutomirski wrote: > Ugh. Some of those files are very useful. Could this perhaps still > allow O_RDONLY if we're in INTEGRITY mode? The previous implementation did, but Greg wanted it to go away entirely.

Re: [PATCH V31 25/25] debugfs: Disable open() when kernel is locked down

2019-03-26 Thread Andy Lutomirski
On Tue, Mar 26, 2019 at 11:28 AM Matthew Garrett wrote: > > From: Matthew Garrett > > debugfs has not been meaningfully audited in terms of ensuring that > userland cannot trample over the kernel. At Greg's request, disable > access to it entirely when the kernel is locked down. This is done at