mbox series

[RFC,0/3] basic KASAN support for Xen PV domains

Message ID 20191217140804.27364-1-sergey.dyasli@citrix.com (mailing list archive)
Headers show
Series basic KASAN support for Xen PV domains | expand

Message

Sergey Dyasli Dec. 17, 2019, 2:08 p.m. UTC 
This series allows to boot and run Xen PV kernels (Dom0 and DomU) with
CONFIG_KASAN=y. It has been used internally for some time now with good
results for finding memory corruption issues in Dom0 kernel.

Only Outline instrumentation is supported at the moment.

Patch 1 is of RFC quality
Patches 2-3 are independent and quite self-contained.

Sergey Dyasli (1):
  x86/xen: add basic KASAN support for PV kernel

Ross Lagerwall (2):
  xen: teach KASAN about grant tables
  xen/netback: Fix grant copy across page boundary with KASAN

 arch/x86/mm/init.c                | 14 ++++++++
 arch/x86/mm/kasan_init_64.c       | 28 ++++++++++++++++
 arch/x86/xen/Makefile             |  7 ++++
 arch/x86/xen/enlighten_pv.c       |  3 ++
 arch/x86/xen/mmu_pv.c             | 13 ++++++--
 arch/x86/xen/multicalls.c         | 10 ++++++
 drivers/net/xen-netback/common.h  |  2 +-
 drivers/net/xen-netback/netback.c | 55 ++++++++++++++++++++++++-------
 drivers/xen/Makefile              |  2 ++
 drivers/xen/grant-table.c         |  5 ++-
 kernel/Makefile                   |  2 ++
 lib/Kconfig.kasan                 |  3 +-
 12 files changed, 128 insertions(+), 16 deletions(-)

Comments

Boris Ostrovsky Dec. 17, 2019, 6:06 p.m. UTC | #1 
> On Dec 17, 2019, at 9:08 AM, Sergey Dyasli <sergey.dyasli@citrix.com> wrote:
> 
> This series allows to boot and run Xen PV kernels (Dom0 and DomU) with
> CONFIG_KASAN=y. It has been used internally for some time now with good
> results for finding memory corruption issues in Dom0 kernel.
> 
> Only Outline instrumentation is supported at the moment.
> 
> Patch 1 is of RFC quality
> Patches 2-3 are independent and quite self-contained.


Don’t you need to initialize kasan before, for example, calling kasan_alloc_pages() in patch 2?

-boris
Sergey Dyasli Dec. 20, 2019, 10:26 a.m. UTC | #2 
On 17/12/2019 18:06, Boris Ostrovsky wrote:
> 
> 
>> On Dec 17, 2019, at 9:08 AM, Sergey Dyasli <sergey.dyasli@citrix.com> wrote:
>>
>> This series allows to boot and run Xen PV kernels (Dom0 and DomU) with
>> CONFIG_KASAN=y. It has been used internally for some time now with good
>> results for finding memory corruption issues in Dom0 kernel.
>>
>> Only Outline instrumentation is supported at the moment.
>>
>> Patch 1 is of RFC quality
>> Patches 2-3 are independent and quite self-contained.
> 
> 
> Don’t you need to initialize kasan before, for example, calling kasan_alloc_pages() in patch 2?

Patch 1 is enough to correctly initialise PV Kasan. But without patch 2, lots
of false positive out-of-bounds accesses are reported once a guest starts using
PV I/O devices.

--
Thanks,
Sergey