pagemap: do not leak physical addresses to non-privileged userspace
authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Mon, 9 Mar 2015 21:11:12 +0000 (23:11 +0200)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 17 Mar 2015 16:31:30 +0000 (09:31 -0700)
commitab676b7d6fbf4b294bf198fb27ade5b0e865c7ce
tree93fdcd656a687ca3fa5f717f9ce078cd8aea6c70
parent06e5801b8cb3fc057d88cb4dc03c0b64b2744cda
pagemap: do not leak physical addresses to non-privileged userspace

As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.

This disallows anybody without CAP_SYS_ADMIN to read the pagemap.

[1] http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html

[ Eventually we might want to do anything more finegrained, but for now
  this is the simple model.   - Linus ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Seaborn <mseaborn@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/proc/task_mmu.c