4.10 kernel on thinkpad x220: rodata_test: test data was not read only

4.10 kernel on thinkpad x220: rodata_test: test data was not read only

[Pavel Machek]

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Hi!

I'm getting

[    3.822386] VFS: Mounted root (ext4 filesystem) readonly on device
8:4.
[    3.840420] devtmpfs: mounted
[    3.842346] Freeing unused kernel memory: 536K
[    3.844081] Write protecting the kernel text: 11764k
[    3.845753] Write protecting the kernel read-only data: 4780k
[    3.847326] rodata_test: test data was not read only
[    3.848906] NX-protecting the kernel data: 6668k
[    3.850662] x86/mm: Checked W+X mappings: passed, no W+X pages
found.

I guess that means that kernel hardening does not work as
expected... 32bit kernel on thinkpad x220.

Git blame points to

commit edeed30589f5defe63ce6aaae56f2b7c855e4520
Author: Arjan van de Ven <arjan@infradead.org>
Date:   Wed Jan 30 13:34:08 2008 +0100

    x86: add testcases for RODATA and NX protections/attributes

Any ideas?
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: 4.10 kernel on thinkpad x220: rodata_test: test data was not read only

[Pavel Machek]

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On Tue 2017-02-21 16:12:01, Arjan van de Ven wrote:
> is NX enabled in the bios?

Yes. (Plus, read-only should work even without NX, right?)

								Pavel


> On Tue, Feb 21, 2017 at 2:14 PM, Pavel Machek <pavel@ucw.cz> wrote:
> 
> > Hi!
> >
> > I'm getting
> >
> > [    3.822386] VFS: Mounted root (ext4 filesystem) readonly on device
> > 8:4.
> > [    3.840420] devtmpfs: mounted
> > [    3.842346] Freeing unused kernel memory: 536K
> > [    3.844081] Write protecting the kernel text: 11764k
> > [    3.845753] Write protecting the kernel read-only data: 4780k
> > [    3.847326] rodata_test: test data was not read only
> > [    3.848906] NX-protecting the kernel data: 6668k
> > [    3.850662] x86/mm: Checked W+X mappings: passed, no W+X pages
> > found.
> >
> > I guess that means that kernel hardening does not work as
> > expected... 32bit kernel on thinkpad x220.
> >
> > Git blame points to
> >
> > commit edeed30589f5defe63ce6aaae56f2b7c855e4520
> > Author: Arjan van de Ven <arjan@infradead.org>
> > Date:   Wed Jan 30 13:34:08 2008 +0100
> >
> >     x86: add testcases for RODATA and NX protections/attributes
> >
> > Any ideas?
> >
> > Pavel
> >
> > --
> > (english) http://www.livejournal.com/~pavelmachek
> > (cesky, pictures) http://atrey.karlin.mff.cuni.
> > cz/~pavel/picture/horses/blog.html
> >

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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