diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index f8e330596664..b71b16da066e 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -141,6 +141,10 @@ void kasan_poison_shadow(const void *address, size_t size, u8 value)
 	 */
 	address = reset_tag(address);
 
+	/* Skip KFENCE memory if called explicitly outside of sl*b. */
+	if (is_kfence_address(address))
+		return;
+
 	shadow_start = kasan_mem_to_shadow(address);
 	shadow_end = kasan_mem_to_shadow(address + size);
 
@@ -158,6 +162,14 @@ void kasan_unpoison_shadow(const void *address, size_t size)
 	 */
 	address = reset_tag(address);
 
+	/*
+	 * Skip KFENCE memory if called explicitly outside of sl*b. Also note
+	 * that calls to ksize(), where size is not a multiple of machine-word
+	 * size, would otherwise poison the invalid portion of the word.
+	 */
+	if (is_kfence_address(address))
+		return;
+
 	kasan_poison_shadow(address, size, tag);
 
 	if (size & KASAN_SHADOW_MASK) {
@@ -497,7 +509,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object,
 	if (unlikely(object == NULL))
 		return NULL;
 
-	if (is_kfence_address(object))
+	if (is_kfence_address(kasan_reset_tag(object)))
 		return (void *)object;
 
 	redzone_start = round_up((unsigned long)(object + size),