kasan-add-test-for-slab_typesafe_by_rcu-quarantine-skipping-v3

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Link: https://lkml.kernel.org/r/20250814-kasan-tsbrcu-noquarantine-test-v3-1-9e9110009b4e@google.com
Signed-off-by: Jann Horn <jannh@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/kasan/kasan_test_c.c b/mm/kasan/kasan_test_c.c
index 47ff5cd941c717b5bc9f9c26bf18b6d63c32b574..4cf2b5f8d6c1459d8d2d0a2ea09574d0a92dbf84 100644 (file)
--- a/mm/kasan/kasan_test_c.c
+++ b/mm/kasan/kasan_test_c.c
@@ -1076,6 +1076,8 @@ static void kmem_cache_rcu_uaf(struct kunit *test)
 /*
  * Check that SLAB_TYPESAFE_BY_RCU objects are immediately reused when
  * CONFIG_SLUB_RCU_DEBUG is off, and stay at the same address.
+ * Without this, KASAN builds would be unable to trigger bugs caused by
+ * SLAB_TYPESAFE_BY_RCU users handling reycled objects improperly.
  */
 static void kmem_cache_rcu_reuse(struct kunit *test)
 {