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authorMarco Elver <elver@google.com>2023-06-14 11:51:16 +0200
committerAndrew Morton <akpm@linux-foundation.org>2023-06-19 16:19:33 -0700
commit452c03fdbed0d19f907c877a6a9edd226b1ebad9 (patch)
tree70957163befd546b5eaa29cc561f7862e3b7b34b /Documentation/dev-tools
parentcb0551adf92dac140d0e0958b4aaa860348bedbb (diff)
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>
Diffstat (limited to 'Documentation/dev-tools')
-rw-r--r--Documentation/dev-tools/kasan.rst7
1 files changed, 4 insertions, 3 deletions
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index e66916a483cd..7f37a46af574 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -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: