diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index b96442960aea..56562ff01076 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -76,12 +76,17 @@
 /*
  * KASAN requires 1/8th of the kernel virtual address space for the shadow
  * region. KASAN can bloat the stack significantly, so double the (minimum)
- * stack size when KASAN is in use.
+ * stack size when KASAN is in use, and then double it again if KASAN_EXTRA is
+ * on.
  */
 #ifdef CONFIG_KASAN
 #define KASAN_SHADOW_SCALE_SHIFT 3
 #define KASAN_SHADOW_SIZE	(UL(1) << (VA_BITS - KASAN_SHADOW_SCALE_SHIFT))
+#ifdef CONFIG_KASAN_EXTRA
+#define KASAN_THREAD_SHIFT	2
+#else
 #define KASAN_THREAD_SHIFT	1
+#endif /* CONFIG_KASAN_EXTRA */
 #else
 #define KASAN_SHADOW_SIZE	(0)
 #define KASAN_THREAD_SHIFT	0