]> git.baikalelectronics.ru Git - kernel.git/commit
drivers/char/hpet.c: allow user controlled mmap for user processes
authorPrarit Bhargava <prarit@redhat.com>
Tue, 12 Nov 2013 23:08:33 +0000 (15:08 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 13 Nov 2013 03:09:11 +0000 (12:09 +0900)
commite9fb554776d88280084ddd5c92f5bdf42e1ed21e
tree9469709ea2eda88e66531edb865ab41757615a0d
parent4a9e5cdfed072a1f2b25f18e76882a1041f6c025
drivers/char/hpet.c: allow user controlled mmap for user processes

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.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Matt Wilson <msw@amazon.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/kernel-parameters.txt
drivers/char/Kconfig
drivers/char/hpet.c