Nicholas Piggin 09495b5f7a powerpc/64s: flush L1D after user accesses ... commit 9a32a7e78b upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache after user accesses. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-11-22 10:14:10 +01:00
..
ABI	iio: improve IIO_CONCENTRATION channel type description	2020-08-19 08:16:07 +02:00
EDID	…
PCI	…
RCU	…
accounting	…
admin-guide	powerpc/64s: flush L1D after user accesses	2020-11-22 10:14:10 +01:00
arm	…
arm64	arm64: errata: Hide CTR_EL0.DIC on systems affected by Neoverse-N1 #1542419	2020-04-29 16:32:56 +02:00
block	…
bpf	…
cdrom	…
core-api	…
cpu-freq	…
crypto	…
dev-tools	…
devicetree	gpio/aspeed-sgpio: enable access to all 80 input & output sgpios	2020-10-07 08:01:28 +02:00
doc-guide	…
driver-api	ata: make qc_prep return ata_completion_errors	2020-10-01 13:18:26 +02:00
fault-injection	…
fb	fbdev: fix numbering of fbcon options	2020-02-24 08:36:42 +01:00
features	…
filesystems	affs: fix basic permission bits to actually work	2020-09-09 19:12:34 +02:00
firmware-guide	…
firmware_class	…
fpga	…
gpu	…
hid	…
hwmon	…
i2c	…
ia64	…
ide	…
iio	…
infiniband	…
input	…
ioctl	…
isdn	…
kbuild	kbuild: support LLVM=1 to switch the default tools to Clang/LLVM	2020-08-26 10:40:47 +02:00
kernel-hacking	…
leds	…
livepatch	…
locking	…
m68k	…
maintainer	…
media	media: videodev2.h: RGB BT2020 and HSV are always full range	2020-11-05 11:43:15 +01:00
mic	…
mips	…
misc-devices	…
netlabel	…
networking	can: j1939: swap addr and pgn in the send example	2020-11-18 19:20:19 +01:00
nios2	…
openrisc	…
parisc	…
pcmcia	…
power	…
powerpc	…
process	…
riscv	…
s390	…
scheduler	…
scsi	…
security	…
sh	…
sound	ALSA: hda/realtek - Remove now-unnecessary XPS 13 headphone noise fixups	2020-04-17 10:50:08 +02:00
sparc	…
sphinx	…
sphinx-static	…
spi	…
target	…
timers	…
trace	…
translations	…
usb	…
userspace-api	…
virt	x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit	2020-06-22 09:30:57 +02:00
virtual	…
vm	…
w1	…
watchdog	…
x86	…
xtensa	…
.gitignore	…
COPYING-logo	…
Changes	…
CodingStyle	…
DMA-API-HOWTO.txt	…
DMA-API.txt	…
DMA-ISA-LPC.txt	…
DMA-attributes.txt	…
IPMI.txt	…
IRQ-affinity.txt	…
IRQ-domain.txt	…
IRQ.txt	…
Kconfig	…
Makefile	…
SubmittingPatches	…
asm-annotations.rst	linkage: Introduce new macros for assembler symbols	2020-11-10 12:37:24 +01:00
atomic_bitops.txt	…
atomic_t.txt	…
bus-virt-phys-mapping.txt	…
conf.py	…
crc32.txt	…
debugging-modules.txt	…
debugging-via-ohci1394.txt	…
digsig.txt	…
docutils.conf	…
dontdiff	…
futex-requeue-pi.txt	…
hwspinlock.txt	…
index.rst	linkage: Introduce new macros for assembler symbols	2020-11-10 12:37:24 +01:00
io-mapping.txt	…
io_ordering.txt	…
irqflags-tracing.txt	…
kobject.txt	…
kprobes.txt	…
kref.txt	…
logo.gif	…
lzo.txt	lib/lzo: fix ambiguous encoding bug in lzo-rle	2020-06-17 16:40:28 +02:00
mailbox.txt	…
memory-barriers.txt	…
nommu-mmap.txt	…
padata.txt	…
percpu-rw-semaphore.txt	…
pi-futex.txt	…
preempt-locking.txt	…
rbtree.txt	…
remoteproc.txt	…
robust-futex-ABI.txt	…
robust-futexes.txt	…
rpmsg.txt	…
speculation.txt	…
static-keys.txt	…
tee.txt	…
this_cpu_ops.txt	…
unaligned-memory-access.txt	…
xz.txt	…