linux/arch
Jann Horn f12d11c5c1 x86/entry/64: Wipe KASAN stack shadow before rewind_stack_do_exit()
Reset the KASAN shadow state of the task stack before rewinding RSP.
Without this, a kernel oops will leave parts of the stack poisoned, and
code running under do_exit() can trip over such poisoned regions and cause
nonsensical false-positive KASAN reports about stack-out-of-bounds bugs.

This does not wipe the exception stacks; if an oops happens on an exception
stack, it might result in random KASAN false-positives from other tasks
afterwards. This is probably relatively uninteresting, since if the kernel
oopses on an exception stack, there are most likely bigger things to worry
about. It'd be more interesting if vmapped stacks and KASAN were
compatible, since then handle_stack_overflow() would oops from exception
stack context.

Fixes: 2deb4be280 ("x86/dumpstack: When OOPSing, rewind the stack before do_exit()")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: kasan-dev@googlegroups.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180828184033.93712-1-jannh@google.com
2018-08-30 11:37:09 +02:00
..
alpha Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2018-08-24 09:25:39 -07:00
arc kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
arm ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
arm64 ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
c6x kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
h8300 Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
hexagon kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
ia64 ia64: Fix allnoconfig section mismatch for ioc_init/ioc_iommu_info 2018-08-22 14:12:47 -07:00
m68k kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
microblaze kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
mips Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
nds32 kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
nios2 mm: convert return type of handle_mm_fault() caller to vm_fault_t 2018-08-17 16:20:28 -07:00
openrisc OpenRISC updates for 4.19 2018-08-23 14:09:37 -07:00
parisc Merge branch 'parisc-4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-08-22 14:06:37 -07:00
powerpc Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax 2018-08-26 11:48:42 -07:00
riscv Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
s390 Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
sh kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
sparc Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
um kbuild: rename LDFLAGS to KBUILD_LDFLAGS 2018-08-24 08:22:08 +09:00
unicore32 mm: convert return type of handle_mm_fault() caller to vm_fault_t 2018-08-17 16:20:28 -07:00
x86 x86/entry/64: Wipe KASAN stack shadow before rewind_stack_do_exit() 2018-08-30 11:37:09 +02:00
xtensa Kbuild updates for v4.19 (2nd) 2018-08-25 13:40:38 -07:00
.gitignore
Kconfig Merge branch 'tlb-fixes' 2018-08-23 14:55:01 -07:00