kasan: add support for kasan.fault=panic_on_write

KASAN's boot time kernel parameter 'kasan.fault=' currently supports
'report' and 'panic', which results in either only reporting bugs or also
panicking on reports.

However, some users may wish to have more control over when KASAN reports
result in a kernel panic: in particular, KASAN reported invalid _writes_
are of special interest, because they have greater potential to corrupt
random kernel memory or be more easily exploited.

To panic on invalid writes only, introduce 'kasan.fault=panic_on_write',
which allows users to choose to continue running on invalid reads, but
panic only on invalid writes.

Link: https://lkml.kernel.org/r/20230614095158.1133673-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Taras Madan <tarasmadan@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Marco Elver
2023-06-14 11:51:16 +02:00
committed by Andrew Morton
parent cb0551adf9
commit 452c03fdbe
2 changed files with 30 additions and 8 deletions

View File

@@ -107,9 +107,10 @@ effectively disables ``panic_on_warn`` for KASAN reports.
Alternatively, independent of ``panic_on_warn``, the ``kasan.fault=`` boot
parameter can be used to control panic and reporting behaviour:
- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
report or also panic the kernel (default: ``report``). The panic happens even
if ``kasan_multi_shot`` is enabled.
- ``kasan.fault=report``, ``=panic``, or ``=panic_on_write`` controls whether
to only print a KASAN report, panic the kernel, or panic the kernel on
invalid writes only (default: ``report``). The panic happens even if
``kasan_multi_shot`` is enabled.
Software and Hardware Tag-Based KASAN modes (see the section about various
modes below) support altering stack trace collection behavior: