Messages in this thread | | | Date | Wed, 28 Aug 2013 23:01:53 -0700 | From | Matt Wilson <> | Subject | Re: [PATCH] hpet, allow user controlled mmap for user processes |
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On Fri, Mar 22, 2013 at 09:32:54AM -0400, Prarit Bhargava wrote: > The CONFIG_HPET_MMAP Kconfig option exposes the memory map of the HPET > registers to userspace. The Kconfig help points out that in some cases this > can be a security risk as some systems may erroneously configure the map such > that additional data is exposed to userspace. > > This is a problem for distributions -- some users want the MMAP functionality > but it comes with a significant security risk. In an effort to mitigate this > risk, and due to the low number of users of the MMAP functionality, I've > introduced a kernel parameter, hpet_mmap_enable, that is required in order > to actually have the HPET MMAP exposed. > > [v2]: Clemens suggested modifying the Kconfig help text and making the > default setting configurable. > [v3]: Fixed up Documentation and Kconfig entries, default now "Y" > [v4]: After testing, found that I need to modify CONFIG_HPET_MMAP_DEFAULT usage > > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > Cc: Clemens Ladisch <clemens@ladisch.de> > --- > Documentation/kernel-parameters.txt | 4 ++++ > drivers/char/Kconfig | 9 +++++++-- > drivers/char/hpet.c | 25 +++++++++++++++++++++++-- > 3 files changed, 34 insertions(+), 4 deletions(-)
It doesn't seem like this patch got picked up and seems like a good idea to me. Clemens, what do you think?
Acked-by: Matt Wilson <msw@amazon.com>
--msw
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