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Linux kernel for uConsole
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Andrey Ryabinin 5e3d10d937 x86/kasan: Fix boot with 5-level paging and KASAN 
commit f3176ec942 upstream.

Since commit d52888aa27 ("x86/mm: Move LDT remap out of KASLR region on
5-level paging") kernel doesn't boot with KASAN on 5-level paging machines.
The bug is actually in early_p4d_offset() and introduced by commit
12a8cc7fcf ("x86/kasan: Use the same shadow offset for 4- and 5-level paging")

early_p4d_offset() tries to convert pgd_val(*pgd) value to a physical
address. This doesn't make sense because pgd_val() already contains the
physical address.

It did work prior to commit d52888aa27 because the result of
"__pa_nodebug(pgd_val(*pgd)) & PTE_PFN_MASK" was the same as "pgd_val(*pgd)
& PTE_PFN_MASK". __pa_nodebug() just set some high bits which were masked
out by applying PTE_PFN_MASK.

After the change of the PAGE_OFFSET offset in commit d52888aa27
__pa_nodebug(pgd_val(*pgd)) started to return a value with more high bits
set and PTE_PFN_MASK wasn't enough to mask out all of them. So it returns a
wrong not even canonical address and crashes on the attempt to dereference
it.

Switch back to pgd_val() & PTE_PFN_MASK to cure the issue.

Fixes: 12a8cc7fcf ("x86/kasan: Use the same shadow offset for 4- and 5-level paging")
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
Cc: stable@vger.kernel.org
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20190614143149.2227-1-aryabinin@virtuozzo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 08:18:06 +02:00
arch x86/kasan: Fix boot with 5-level paging and KASAN 2019-06-19 08:18:06 +02:00
block block, bfq: increase idling for weight-raised queues 2019-06-15 11:54:10 +02:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: ccm - fix incompatibility between "ccm" and "ccm_base" 2019-05-22 07:37:43 +02:00
Documentation tcp: add tcp_min_snd_mss sysctl 2019-06-17 19:51:56 +02:00
drivers RAS/CEC: Fix binary search function 2019-06-19 08:18:06 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs f2fs: fix to avoid accessing xattr across the boundary 2019-06-19 08:18:02 +02:00
include x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback 2019-06-19 08:18:06 +02:00
init initramfs: free initrd memory if opening /initrd.image fails 2019-06-15 11:54:01 +02:00
ipc ipc: prevent lockup on alloc_msg and free_msg 2019-06-15 11:54:00 +02:00
kernel timekeeping: Repair ktime_get_coarse*() granularity 2019-06-19 08:18:06 +02:00
lib test_firmware: Use correct snprintf() limit 2019-06-11 12:20:54 +02:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/vmscan.c: fix trying to reclaim unevictable LRU page 2019-06-19 08:18:00 +02:00
net tcp: enforce tcp_min_snd_mss in tcp_mtu_probing() 2019-06-17 19:51:56 +02:00
samples samples: mei: use /dev/mei0 instead of /dev/mei 2019-02-15 08:10:11 +01:00
scripts gcc-plugins: Fix build failures under Darwin host 2019-06-09 09:17:22 +02:00
security evm: check hash algorithm passed to init_desc() 2019-06-09 09:17:21 +02:00
sound Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" 2019-06-19 08:18:01 +02:00
tools tools/kvm_stat: fix fields filter for child events 2019-06-19 08:18:05 +02:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt KVM: arm/arm64: Move cc/it checks under hyp's Makefile to avoid instrumentation 2019-06-19 08:18:04 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.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 libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS platform/x86: Add Intel AtomISP2 dummy / power-management driver 2019-04-20 09:16:02 +02:00
Makefile Linux 4.19.52 2019-06-17 19:51:57 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

README 

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.