--- xnu/xnu-12377.101.15/libkern/c++/OSData.cpp
+++ xnu/xnu-8020.140.41/libkern/c++/OSData.cpp
@@ -78,8 +78,8 @@
 		if (capacity) {
 			OSCONTAINER_ACCUMSIZE(-(size_t)capacity);
 			/* can't use kfree() as we need to pass Z_MAY_COPYINMAP */
-			__kheap_realloc(KHEAP_DATA_PRIVATE, data, capacity, 0,
-			    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_FULLSIZE | Z_MAY_COPYINMAP,
+			__kheap_realloc(KHEAP_DATA_BUFFERS, data, capacity, 0,
+			    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_MAY_COPYINMAP,
 			    VM_KERN_MEMORY_LIBKERN), (void *)&this->data);
 			data     = nullptr;
 			capacity = 0;
@@ -89,8 +89,11 @@
 		 * Nothing to change
 		 */
 	} else {
-		kr = kalloc_ext(KHEAP_DATA_PRIVATE, inCapacity,
-		    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_FULLSIZE | Z_MAY_COPYINMAP,
+		if (inCapacity >= PAGE_SIZE) {
+			inCapacity = (uint32_t)round_page(inCapacity);
+		}
+		kr = kalloc_ext(KHEAP_DATA_BUFFERS, inCapacity,
+		    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_MAY_COPYINMAP,
 		    VM_KERN_MEMORY_LIBKERN), (void *)&this->data);
 
 		if (kr.addr) {
@@ -225,7 +228,7 @@
 {
 	if ((capacity != EXTERNAL) && data && capacity) {
 		/* can't use kfree() as we need to pass Z_MAY_COPYINMAP */
-		__kheap_realloc(KHEAP_DATA_PRIVATE, data, capacity, 0,
+		__kheap_realloc(KHEAP_DATA_BUFFERS, data, capacity, 0,
 		    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_FULLSIZE | Z_MAY_COPYINMAP,
 		    VM_KERN_MEMORY_LIBKERN), (void *)&this->data);
 		OSCONTAINER_ACCUMSIZE( -((size_t)capacity));
@@ -284,8 +287,11 @@
 		return capacity;
 	}
 
-	kr = krealloc_ext(KHEAP_DATA_PRIVATE, data, capacity, finalCapacity,
-	    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_FULLSIZE | Z_MAY_COPYINMAP,
+	if (finalCapacity >= PAGE_SIZE) {
+		finalCapacity = (uint32_t)round_page(finalCapacity);
+	}
+	kr = krealloc_ext((void *)KHEAP_DATA_BUFFERS, data, capacity, finalCapacity,
+	    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_MAY_COPYINMAP,
 	    VM_KERN_MEMORY_LIBKERN), (void *)&this->data);
 
 	if (kr.addr) {
@@ -319,7 +325,7 @@
 	 * address stable.
 	 */
 	if (length >= msg_ool_size_small && newCapacity < capacity) {
-		kr = krealloc_ext(KHEAP_DATA_PRIVATE,
+		kr = krealloc_ext((void *)KHEAP_DATA_BUFFERS,
 		    data, capacity, newCapacity,
 		    Z_VM_TAG_BT(Z_WAITOK_ZERO | Z_FULLSIZE | Z_MAY_COPYINMAP,
 		    VM_KERN_MEMORY_LIBKERN), (void *)&this->data);