[PATCH 0/5] mm/kasan: advanced check

[Wengang Wang <wen.gang.wang@oracle.com>]

Kasan advanced check, I'm going to add this feature.
Currently Kasan provide the detection of use-after-free and out-of-bounds
problems. It is not able to find the overwrite-on-allocated-memory issue.
We sometimes hit this kind of issue: We have a messed up structure
(usually dynamially allocated), some of the fields in the structure were
overwritten with unreasaonable values. And kernel may panic due to those
overeritten values. We know those fields were overwritten somehow, but we
have no easy way to find out which path did the overwritten. The advanced
check wants to help in this scenario.

The idea is to define the memory owner. When write accesses come from
non-owner, error should be reported. Normally the write accesses on a given
structure happen in only several or a dozen of functions if the structure
is not that complicated. We call those functions "allowed functions".
The work of defining the owner and binding memory to owner is expected to
be done by the memory consumer. In the above case, memory consume register
the owner as the functions which have write accesses to the structure then
bind all the structures to the owner. Then kasan will do the "owner check"
after the basic checks.

As implementation, kasan provides a API to it's user to register their
allowed functions. The API returns a token to users.  At run time, users
bind the memory ranges they are interested in to the check they registered.
Kasan then checks the bound memory ranges with the allowed functions.


Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>

0001-mm-kasan-make-space-in-shadow-bytes-for-advanced-che.patch
0002-mm-kasan-pass-access-mode-to-poison-check-functions.patch
0003-mm-kasan-do-advanced-check.patch
0004-mm-kasan-register-check-and-bind-it-to-memory.patch
0005-mm-kasan-add-advanced-check-test-case.patch

 include/linux/kasan.h |   16 ++
 lib/test_kasan.c      |   73 ++++++++++++
 mm/kasan/kasan.c      |  292 +++++++++++++++++++++++++++++++++++++++++++-------
 mm/kasan/kasan.h      |   42 +++++++
 mm/kasan/report.c     |   44 ++++++-
 5 files changed, 424 insertions(+), 43 deletions(-)

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