Dave Hansen acd547b298 x86/pkeys: Default to a restrictive init PKRU ... PKRU is the register that lets you disallow writes or all access to a given protection key. The XSAVE hardware defines an "init state" of 0 for PKRU: its most permissive state, allowing access/writes to everything. Since we start off all new processes with the init state, we start all processes off with the most permissive possible PKRU. This is unfortunate. If a thread is clone()'d [1] before a program has time to set PKRU to a restrictive value, that thread will be able to write to all data, no matter what pkey is set on it. This weakens any integrity guarantees that we want pkeys to provide. To fix this, we define a very restrictive PKRU to override the XSAVE-provided value when we create a new FPU context. We choose a value that only allows access to pkey 0, which is as restrictive as we can practically make it. This does not cause any practical problems with applications using protection keys because we require them to specify initial permissions for each key when it is allocated, which override the restrictive default. In the end, this ensures that threads which do not know how to manage their own pkey rights can not do damage to data which is pkey-protected. I would have thought this was a pretty contrived scenario, except that I heard a bug report from an MPX user who was creating threads in some very early code before main(). It may be crazy, but folks evidently _do_ it. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-arch@vger.kernel.org Cc: Dave Hansen <dave@sr71.net> Cc: mgorman@techsingularity.net Cc: arnd@arndb.de Cc: linux-api@vger.kernel.org Cc: linux-mm@kvack.org Cc: luto@kernel.org Cc: akpm@linux-foundation.org Cc: torvalds@linux-foundation.org Link: http://lkml.kernel.org/r/20160729163021.F3C25D4A@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>		2016-09-09 13:02:28 +02:00
..
ABI	documentation: drivers/core/of: fix name of of_node symlink	2016-08-31 15:14:44 +02:00
accounting	taskstats: fix nl parsing in accounting/getdelays.c	2016-04-27 12:50:14 -04:00
acpi	Merge branches 'acpi-bus', 'acpi-pci', 'acpica' and 'acpi-doc'	2016-07-25 13:41:25 +02:00
aoe
arm	ARM: at91: Documentation: update the sama5d2 entry	2016-06-21 17:09:34 +02:00
arm64	arm64: Document workaround for Cortex-A72 erratum #853709	2016-08-17 12:23:47 +02:00
auxdisplay
backlight
blackfin
block	doc: update block/queue-sysfs.txt entries	2016-08-11 09:37:23 -06:00
blockdev	zram: cosmetic: cleanup documentation	2016-07-26 16:19:19 -07:00
bus-devices
cdrom
cgroup-v1	Three fixes for the docs build, including removing an annoying warning on	2016-08-07 10:23:17 -04:00
cma
connector	samples: connector: from Documentation to samples directory	2016-04-28 07:47:35 -06:00
console
cpu-freq	Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency"	2016-07-22 23:51:06 +02:00
cpuidle
cris
crypto	crypto: doc - Fix typo	2016-05-31 16:41:55 +08:00
development-process	docs: deprecate kernel-doc-nano-HOWTO.txt	2016-07-20 16:45:37 -06:00
device-mapper	block: rename bio bi_rw to bi_opf	2016-08-07 14:41:02 -06:00
devicetree	Staging/IIO driver fixes for 4.8-rc5	2016-09-03 11:33:33 -07:00
dmaengine	Documentation: dmaengine: fix typo for device_resume	2016-06-03 14:00:21 -06:00
DocBook	Three fixes for the docs build, including removing an annoying warning on	2016-08-07 10:23:17 -04:00
driver-model	ARM: SoC driver updates for v4.8	2016-08-01 18:36:01 -04:00
early-userspace
EDID
extcon
fault-injection	net: Add support for CHANGEUPPER notifier error injection	2015-12-03 11:49:23 -05:00
fb	Documentation: fb: fix spelling mistakes	2016-05-10 12:05:27 +03:00
features	powerpc: Add HAVE_PERF_USER_STACK_DUMP support	2016-05-11 21:54:05 +10:00
filesystems	ovl: update doc	2016-09-01 11:12:00 +02:00
firmware_class	Documentation: fix common spelling mistakes	2016-04-28 07:51:59 -06:00
fmc
fpga
frv
gpio	gpio: Fix paths to GPIO driver source files	2016-06-13 09:30:31 +02:00
gpu	drm: add generic zpos property	2016-07-29 09:59:30 +02:00
hid	HID: add Alps I2C HID Touchpad-Stick support	2016-06-17 23:12:04 +02:00
hwmon	hwmon: (ftsteutates) Correct ftp urls in driver documentation	2016-08-12 05:56:34 -07:00
i2c	Documentation: i2c: slave: give proper example for pm usage	2016-07-23 22:04:20 +02:00
ia64
ide
iio	iio: Documentation: Add IIO configfs documentation	2015-12-03 18:19:28 +00:00
infiniband	Round two of 4.7 merge window patches	2016-05-28 11:04:16 -07:00
input	Input: clarify we want BTN_TOOL_<name> on proximity	2016-04-06 10:23:09 -07:00
ioctl	nilfs2: move ioctl interface and disk layout to uapi separately	2016-08-02 19:35:21 -04:00
isdn	isdn: i4l: move active-isdn drivers to staging	2016-03-05 15:00:38 -08:00
ja_JP	Documentatio: HOWTO: remove regression postings info from translations	2016-04-16 10:49:08 -06:00
kbuild	kbuild, x86: Track generated headers with generated-y	2016-07-07 15:58:44 +02:00
kdump	kdump: fix dmesg gdbmacro to work with record based printk	2016-06-03 15:06:22 -07:00
ko_KR	Documentation: HOWTO: update git home URL in translations	2016-04-16 10:49:18 -06:00
laptops	leds: documentation: 'ide-disk' to 'disk-activity'	2016-06-27 08:58:35 +02:00
leds	leds: documentation: 'ide-disk' to 'disk-activity'	2016-06-27 08:58:35 +02:00
livepatch	Merge branches 'for-4.7/core', 'for-4.7/livepatching-doc' and 'for-4.7/livepatching-ppc64' into for-linus	2016-05-17 12:06:35 +02:00
locking	locking/Documentation/lockdep: Fix spelling mistakes	2016-04-28 10:40:57 +02:00
m68k
media	[media] cx23885-cardlist.rst: add a new card	2016-07-23 08:14:48 -03:00
memory-devices
metag
mic	mpssd: fix buffer overflow warning	2016-06-03 13:31:37 -06:00
mips
misc-devices	Merge char-misc-next into staging-next	2016-02-22 14:46:24 -08:00
mmc	mmc: core: Extend sysfs with DSR register	2016-07-25 10:34:51 +02:00
mn10300
mtd	Documentation: mtd: improve nand_ecc.txt for readability and correctness	2015-11-17 17:05:14 -08:00
namespaces
netlabel
networking	Documentation: networking: dsa: Remove platform device TODO	2016-08-28 23:43:06 -04:00
nfc
nios2
nvdimm	libnvdimm, btt: update the usage section in Documentation	2016-06-17 16:23:23 -07:00
nvmem
parisc
PCI	treewide: remove references to the now unnecessary DEFINE_PCI_DEVICE_TABLE	2016-09-01 17:52:01 -07:00
pcmcia
phy
platform
power	PM / sleep: Update some system sleep documentation	2016-08-13 02:54:04 +02:00
powerpc	powerpc: signals: Discard transaction state from signal frames	2016-08-29 12:48:40 +10:00
pps	Documentation: pps: fix spelling mistake	2016-04-28 07:23:59 -06:00
prctl	Documentation: Fix int/unsigned int comparison	2016-02-17 14:09:43 -07:00
pti
ptp	Another relatively boring cycle for the docs tree: typo fixes, translation	2016-03-17 12:09:35 -07:00
rapidio	rapidio/documentation/mport_cdev: add missing parameter description	2016-09-01 17:52:02 -07:00
RCU	Documentation: Fix spelling mistake	2016-06-14 16:01:00 -07:00
s390	s390/Documentation: improve sort command for trace buffer	2016-06-13 15:58:23 +02:00
scheduler	Documenation: update cgroup's document path	2016-08-03 15:43:58 -06:00
scsi	Merge remote-tracking branch 'mkp-scsi/4.7/scsi-fixes' into fixes	2016-06-18 11:59:01 -07:00
security	Some big changes this month, headlined by the addition of a new formatted	2016-07-26 13:05:11 -07:00
serial	TTY and Serial driver update for 4.7-rc1	2016-05-20 20:57:27 -07:00
sh
sound	ASoC: Updates for v4.8	2016-07-26 10:35:31 +02:00
sphinx	Merge branch 'docs-next' of git://git.lwn.net/linux into topic/docs-next	2016-07-23 07:55:59 -03:00
sphinx-static	doc-rst: customize RTD theme, drop padding of inline literal	2016-08-14 12:15:09 -06:00
spi	spi: tools: move spidev_test metadata	2015-11-30 12:14:12 +00:00
sysctl	printk: add kernel parameter to control writes to /dev/kmsg	2016-08-02 19:35:06 -04:00
target	target: make close_session optional	2016-05-10 01:19:26 -07:00
thermal	Doc: PM: Fix a typo in intel_powerclamp.txt	2016-06-30 13:05:40 -06:00
timers	Documentation: fix common spelling mistakes	2016-04-28 07:51:59 -06:00
tpm	tpm: Add documentation for the tpm_vtpm_proxy device driver	2016-06-25 17:26:35 +03:00
trace	tracing: expose current->comm to [ku]probe events	2016-06-20 09:54:19 -04:00
usb	Documentation: tiny typo fix in usb/gadget_multi.txt	2016-06-23 08:09:10 -06:00
vDSO
virtual	KVM: documentation: fix KVM_CAP_X2APIC_API information	2016-08-04 14:01:21 +02:00
vm	Three fixes for the docs build, including removing an annoying warning on	2016-08-07 10:23:17 -04:00
w1	w1: add ability to set (SRAM) and store (EEPROM) configuration for temp sensors like DS18B20	2016-05-01 14:37:49 -07:00
watchdog	Documentation/watchdog: check return value for magic close	2016-07-25 11:02:17 +02:00
wimax
x86	pkeys: Add details of system call use to Documentation/	2016-09-09 13:02:28 +02:00
xtensa
zh_CN	docs: deprecate kernel-doc-nano-HOWTO.txt	2016-07-20 16:45:37 -06:00
.gitignore	Add .pyc files to .gitignore	2016-06-30 13:07:33 -06:00
00-INDEX	docs: deprecate kernel-doc-nano-HOWTO.txt	2016-07-20 16:45:37 -06:00
adding-syscalls.txt	documentation: trivial typo: adding-syscalls.txt: s/statat/fstatat/	2016-04-18 11:31:49 -06:00
applying-patches.txt
assoc_array.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
bcache.txt	bcache: documentation formatting, edited for clarity, stripe alignment notes	2016-06-23 07:58:38 -06:00
binfmt_misc.txt	binfmt_misc: add F option description to documentation	2016-03-30 14:12:22 -07:00
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
cec.txt	[media] cec.txt: add CEC framework documentation	2016-06-22 08:36:50 -03:00
cgroup-v2.txt	Merge branch 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2016-03-21 10:05:13 -07:00
Changes	There is a nice new document from Neil on how pathname lookups work and	2015-11-05 15:59:24 -08:00
circular-buffers.txt
clk.txt
coccinelle.txt	coccicheck: refer to Documentation/coccinelle.txt and wiki	2016-07-22 12:13:39 +02:00
CodeOfConflict
CodingStyle	docs: deprecate kernel-doc-nano-HOWTO.txt	2016-07-20 16:45:37 -06:00
conf.py	docs: Set the Sphinx default highlight language to "guess"	2016-08-12 14:11:12 -06:00
cpu-hotplug.txt	Documentation: cpu-hotplug: Fix sysfs mount instructions	2015-12-10 11:35:30 -07:00
cpu-load.txt
cputopology.txt	topology/sysfs: provide drawer id and siblings attributes	2016-06-13 15:58:27 +02:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
devices.txt	Documentation: update the devices.txt documentation	2016-03-29 10:11:44 -07:00
digsig.txt
DMA-API-HOWTO.txt	dma-mapping: always provide the dma_map_ops based implementation	2016-01-20 17:09:18 -08:00
DMA-API.txt	dma-mapping: use unsigned long for dma_attrs	2016-08-04 08:50:07 -04:00
DMA-attributes.txt	dma-mapping: use unsigned long for dma_attrs	2016-08-04 08:50:07 -04:00
dma-buf-sharing.txt	dma-buf: Update docs for SYNC ioctl	2016-03-21 09:26:45 +01:00
DMA-ISA-LPC.txt
dontdiff	GCC plugin infrastructure	2016-06-07 22:57:10 +02:00
dynamic-debug-howto.txt
edac.txt	EDAC: Remove references to bluesmoke.sourceforge.net	2015-11-26 14:46:06 +01:00
efi-stub.txt	doc: efi-stub.txt: Fix arm64 paths	2015-12-14 15:24:03 +00:00
eisa.txt
email-clients.txt	A few more documentation patches that wandered in and have no reason to	2015-11-13 09:19:05 -08:00
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt	GCC plugin infrastructure	2016-06-07 22:57:10 +02:00
gcov.txt
gdb-kernel-debugging.txt	Revert "scripts/gdb: add documentation example for radix tree"	2016-07-15 14:54:27 +09:00
highuid.txt
HOWTO	Documentation: Howto: Fixed subtitles style	2016-03-09 15:30:03 -07:00
hsi.txt
hw_random.txt
hwspinlock.txt
index.rst	Merge tag 'drm-for-v4.8' of git://people.freedesktop.org/~airlied/linux	2016-08-01 21:44:08 -04:00
init.txt
initrd.txt
intel_txt.txt
Intel-IOMMU.txt	iommu/vt-d: Fix link to Intel IOMMU Specification	2016-01-29 12:32:12 +01:00
io_ordering.txt
io-mapping.txt
iostats.txt
IPMI.txt	ipmi watchdog : add panic_wdt_timeout parameter	2015-11-16 06:28:43 -06:00
IRQ-affinity.txt
IRQ-domain.txt	Documentation/IRQ-domain.txt: Document irq_domain_create_{linear, tree}	2016-03-31 00:32:59 -06:00
IRQ.txt
irqflags-tracing.txt
isa.txt	Documentation: Add ISA bus driver documentation	2016-05-02 09:32:04 -07:00
isapnp.txt
java.txt
kasan.txt	mm, kasan: SLAB support	2016-03-25 16:37:42 -07:00
kcov.txt	kernel: add kcov code coverage	2016-03-22 15:36:02 -07:00
kernel-doc-nano-HOWTO.txt	docs: deprecate kernel-doc-nano-HOWTO.txt	2016-07-20 16:45:37 -06:00
kernel-docs.txt	Documentation: update Michael K. Johnson's work	2016-04-15 15:37:25 -06:00
kernel-documentation.rst	docs: kernel-documentation: remove some highlight directives	2016-08-12 15:12:36 -06:00
kernel-parameters.txt	x86/pkeys: Default to a restrictive init PKRU	2016-09-09 13:02:28 +02:00
kernel-per-CPU-kthreads.txt	Documenation: update cgroup's document path	2016-08-03 15:43:58 -06:00
kmemcheck.txt
kmemleak.txt
kobject.txt
kprobes.txt
kref.txt
kselftest.txt	Documentation: kselftest: Remove duplicate word	2016-03-09 15:33:38 -07:00
ldm.txt
local_ops.txt
lockup-watchdogs.txt	kernel/watchdog.c: add sysctl knob hardlockup_panic	2015-11-05 19:34:48 -08:00
logo.gif
logo.txt
lzo.txt	Documentation: lzo: fix spelling mistakes	2016-04-28 07:23:11 -06:00
magic-number.txt
mailbox.txt
Makefile	[media] samples: v4l: from Documentation to samples directory	2016-05-09 18:34:37 -03:00
Makefile.sphinx	Three fixes for the docs build, including removing an annoying warning on	2016-08-07 10:23:17 -04:00
ManagementStyle
md-cluster.txt	md-cluster: change array_sectors and update size are not supported	2016-05-04 12:39:35 -07:00
md.txt	Documentation: fix wrong value in md.txt	2016-06-23 08:08:36 -06:00
memory-barriers.txt	locking/Documentation: Clarify limited control-dependency scope	2016-06-17 09:54:45 +02:00
memory-hotplug.txt	memory_hotplug: introduce CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE	2016-05-19 19:12:14 -07:00
men-chameleon-bus.txt
module-signing.txt	Documentation/module-signing.txt: Note need for version info if reusing a key	2016-07-27 12:38:00 +09:30
mono.txt
nommu-mmap.txt
ntb.txt
numastat.txt
oops-tracing.txt
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt
phy.txt	phy: core: Allow children node to be overridden	2016-04-29 16:39:39 +02:00
pi-futex.txt
pinctrl.txt	pinctrl: Flag strict is a field in struct pinmux_ops	2016-06-23 10:50:10 +02:00
pnp.txt
preempt-locking.txt
printk-formats.txt	mm, printk: introduce new format string for flags	2016-03-15 16:55:16 -07:00
pwm.txt	pwm: Update documentation	2016-05-17 14:48:04 +02:00
ramoops.txt	ramoops: use DT reserved-memory bindings	2016-08-05 11:21:36 -07:00
rbtree.txt
remoteproc.txt
rfkill.txt	rfkill: Add documentation about LED triggers	2016-02-24 09:13:12 +01:00
robust-futex-ABI.txt
robust-futexes.txt	Documentation: robust-futexes: fix spelling mistakes	2016-04-28 07:26:41 -06:00
rpmsg.txt	rpmsg: use module_rpmsg_driver in existing drivers and examples	2016-05-06 11:09:01 -07:00
rtc.txt	rtc: implement a sysfs interface for clock offset	2016-03-14 17:08:16 +01:00
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
SM501.txt
smsc_ece1099.txt
sparse.txt
stable_api_nonsense.txt
stable_kernel_rules.txt	stable_kernel_rules.txt: Remove extra space after Cc:	2015-11-20 16:54:57 -07:00
static-keys.txt
SubmitChecklist
SubmittingDrivers
SubmittingPatches	SubmittingPatches: fix spelling of "git send-email"	2016-01-25 12:30:18 -07:00
svga.txt
sync_file.txt	Documentation: Fix some grammar mistakes in sync_file.txt	2016-06-03 13:24:16 -06:00
sysfs-rules.txt
sysrq.txt	Doc: correct the location of sysrq.c	2016-04-28 08:02:36 -06:00
this_cpu_ops.txt
ubsan.txt	UBSAN: run-time undefined behavior sanity checker	2016-01-20 17:09:18 -08:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
vfio.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt	workqueue: Fix a typo in workqueue.txt	2016-07-06 02:37:38 -06:00
xillybus.txt	Documentation: xillybus: fix spelling mistake	2016-04-28 07:44:54 -06:00
xz.txt
zorro.txt