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Huang Ying ab6ecf247a mm: /proc/pid/pagemap: hide swap entries from unprivileged users
In commit ab676b7d6f ("pagemap: do not leak physical addresses to
non-privileged userspace"), the /proc/PID/pagemap is restricted to be
readable only by CAP_SYS_ADMIN to address some security issue.

In commit 1c90308e7a ("pagemap: hide physical addresses from
non-privileged users"), the restriction is relieved to make
/proc/PID/pagemap readable, but hide the physical addresses for
non-privileged users.

But the swap entries are readable for non-privileged users too.  This
has some security issues.  For example, for page under migrating, the
swap entry has physical address information.  So, in this patch, the
swap entries are hided for non-privileged users too.

Link: http://lkml.kernel.org/r/20180508012745.7238-1-ying.huang@intel.com
Fixes: 1c90308e7a ("pagemap: hide physical addresses from non-privileged users")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Suggested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Daniel Colascione <dancol@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:36 -07:00
arch mm: introduce ARCH_HAS_PTE_SPECIAL 2018-06-07 17:34:35 -07:00
block Changes for 4.18: 2018-06-05 13:24:20 -07:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto - Introduce arithmetic overflow test helper functions (Rasmus) 2018-06-06 17:27:14 -07:00
Documentation mm/docs: describe memory.low refinements 2018-06-07 17:34:35 -07:00
drivers zram: introduce zram memory tracking 2018-06-07 17:34:34 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs mm: /proc/pid/pagemap: hide swap entries from unprivileged users 2018-06-07 17:34:36 -07:00
include memcg: writeback: use memcg->cgwb_list directly 2018-06-07 17:34:36 -07:00
init Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
ipc Merge branch 'timers-2038-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 21:02:18 -07:00
kernel mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct 2018-06-07 17:34:34 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm mm/memblock: print memblock_remove 2018-06-07 17:34:36 -07:00
net net/9p/trans_xen.c: don't inclide rwlock.h directly 2018-06-07 17:34:34 -07:00
samples samples/bpf: xdpsock: use skb Tx path for XDP_SKB 2018-06-05 15:48:57 +02:00
scripts scripts: use SPDX tag in get_maintainer and checkpatch 2018-06-07 17:34:33 -07:00
security Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
sound media updates for v4.18-rc1 2018-06-07 12:34:37 -07:00
tools powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-06-04 15:23:48 -07:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge branch 'asoc-4.17' into asoc-4.18 for compress dependencies 2018-04-26 12:24:28 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: add basic helper macros to scripts/Kconfig.include 2018-05-29 03:31:19 +09:00
MAINTAINERS media updates for v4.18-rc1 2018-06-07 12:34:37 -07:00
Makefile Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-06-06 18:39:49 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.