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Vincenzo Frascino 23713b480d mm/vmalloc.c: fix kasan shadow poisoning size
[ Upstream commit c041098c690fe53cea5d20c62f128a4f7a5c19fe ]

The size of vm area can be affected by the presence or not of the guard
page.  In particular when VM_NO_GUARD is present, the actual accessible
size has to be considered like the real size minus the guard page.

Currently kasan does not keep into account this information during the
poison operation and in particular tries to poison the guard page as well.

This approach, even if incorrect, does not cause an issue because the tags
for the guard page are written in the shadow memory.  With the future
introduction of the Tag-Based KASAN, being the guard page inaccessible by
nature, the write tag operation on this page triggers a fault.

Fix kasan shadow poisoning size invoking get_vm_area_size() instead of
accessing directly the field in the data structure to detect the correct
value.

Link: https://lkml.kernel.org/r/20201027160213.32904-1-vincenzo.frascino@arm.com
Fixes: d98c9e83b5 ("kasan: fix crashes on access to memory mapped by vm_map_ram()")
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-30 11:53:55 +01:00
arch sparc: fix handling of page table constructor failure 2020-12-30 11:53:55 +01:00
block block-5.10-2020-12-05 2020-12-05 14:45:30 -08:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: Kconfig - CRYPTO_MANAGER_EXTRA_TESTS requires the manager 2020-12-30 11:53:09 +01:00
Documentation USB: UAS: introduce a quirk to set no_write_same 2020-12-21 13:30:08 +01:00
drivers mm/gup: prevent gup_fast from racing with COW during fork 2020-12-30 11:53:54 +01:00
fs ubifs: Fix error return code in ubifs_init_authentication() 2020-12-30 11:53:52 +01:00
include mm/rmap: always do TTU_IGNORE_ACCESS 2020-12-30 11:53:55 +01:00
init initramfs: fix clang build failure 2020-12-11 14:02:14 -08:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel mm/gup: prevent gup_fast from racing with COW during fork 2020-12-30 11:53:54 +01:00
lib selftest/fpu: avoid clang warning 2020-12-11 14:02:14 -08:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/vmalloc.c: fix kasan shadow poisoning size 2020-12-30 11:53:55 +01:00
net sunrpc: fix xs_read_xdr_buf for partial pages receive 2020-12-30 11:53:53 +01:00
samples samples/bpf: Fix possible hang in xdpsock with multiple threads 2020-12-30 11:53:49 +01:00
scripts scripts: kernel-doc: fix parsing function-like typedefs 2020-12-30 11:53:33 +01:00
security selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling 2020-12-30 11:53:03 +01:00
sound ASoC: wm_adsp: remove "ctl" from list on error in wm_adsp_create_control() 2020-12-30 11:53:50 +01:00
tools perf test: Fix metric parsing test 2020-12-30 11:53:54 +01:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt kvm: x86/mmu: Support dirty logging for the TDP MMU 2020-10-23 03:42:13 -04:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-10 15:30:13 -08:00
Makefile Linux 5.10.3 2020-12-26 16:02:46 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -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.

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.