diff --git a/include/linux/kexec_handover.h b/include/linux/kexec_handover.h
index 0666cf298c7f..8968c56d2d73 100644
--- a/include/linux/kexec_handover.h
+++ b/include/linux/kexec_handover.h
@@ -34,7 +34,7 @@ struct page *kho_restore_pages(phys_addr_t phys, unsigned long nr_pages);
 void *kho_restore_vmalloc(const struct kho_vmalloc *preservation);
 int kho_add_subtree(const char *name, void *blob, size_t size);
 void kho_remove_subtree(void *blob);
-int kho_retrieve_subtree(const char *name, phys_addr_t *phys);
+int kho_retrieve_subtree(const char *name, phys_addr_t *phys, size_t *size);
 
 void kho_memory_init(void);
 
@@ -104,7 +104,8 @@ static inline int kho_add_subtree(const char *name, void *blob, size_t size)
 
 static inline void kho_remove_subtree(void *blob) { }
 
-static inline int kho_retrieve_subtree(const char *name, phys_addr_t *phys)
+static inline int kho_retrieve_subtree(const char *name, phys_addr_t *phys,
+				       size_t *size)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/include/linux/kho/abi/kexec_handover.h b/include/linux/kho/abi/kexec_handover.h
index 6b7d8ef550f9..7e847a2339b0 100644
--- a/include/linux/kho/abi/kexec_handover.h
+++ b/include/linux/kho/abi/kexec_handover.h
@@ -41,25 +41,28 @@
  *   restore the preserved data.::
  *
  *     / {
- *         compatible = "kho-v2";
+ *         compatible = "kho-v3";
  *
  *         preserved-memory-map = <0x...>;
  *
  *         <subnode-name-1> {
  *             preserved-data = <0x...>;
+ *             blob-size = <0x...>;
  *         };
  *
  *         <subnode-name-2> {
  *             preserved-data = <0x...>;
+ *             blob-size = <0x...>;
  *         };
  *               ... ...
  *         <subnode-name-N> {
  *             preserved-data = <0x...>;
+ *             blob-size = <0x...>;
  *         };
  *     };
  *
  *   Root KHO Node (/):
- *     - compatible: "kho-v2"
+ *     - compatible: "kho-v3"
  *
  *       Indentifies the overall KHO ABI version.
  *
@@ -78,16 +81,25 @@
  *
  *       Physical address pointing to a subnode data blob that is also
  *       being preserved.
+ *
+ *     - blob-size: u64
+ *
+ *       Size in bytes of the preserved data blob. This is needed because
+ *       blobs may use arbitrary formats (not just FDT), so the size
+ *       cannot be determined from the blob content alone.
  */
 
 /* The compatible string for the KHO FDT root node. */
-#define KHO_FDT_COMPATIBLE "kho-v2"
+#define KHO_FDT_COMPATIBLE "kho-v3"
 
 /* The FDT property for the preserved memory map. */
 #define KHO_FDT_MEMORY_MAP_PROP_NAME "preserved-memory-map"
 
 /* The FDT property for preserved data blobs. */
-#define KHO_FDT_SUB_TREE_PROP_NAME "preserved-data"
+#define KHO_SUB_TREE_PROP_NAME "preserved-data"
+
+/* The FDT property for the size of preserved data blobs. */
+#define KHO_SUB_TREE_SIZE_PROP_NAME "blob-size"
 
 /**
  * DOC: Kexec Handover ABI for vmalloc Preservation
diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c
index 711b6c3376e7..adf6541f70f9 100644
--- a/kernel/liveupdate/kexec_handover.c
+++ b/kernel/liveupdate/kexec_handover.c
@@ -743,6 +743,7 @@ int kho_add_subtree(const char *name, void *blob, size_t size)
 {
 	phys_addr_t phys = virt_to_phys(blob);
 	void *root_fdt = kho_out.fdt;
+	u64 size_u64 = size;
 	int err = -ENOMEM;
 	int off, fdt_err;
 
@@ -759,11 +760,16 @@ int kho_add_subtree(const char *name, void *blob, size_t size)
 		goto out_pack;
 	}
 
-	err = fdt_setprop(root_fdt, off, KHO_FDT_SUB_TREE_PROP_NAME,
+	err = fdt_setprop(root_fdt, off, KHO_SUB_TREE_PROP_NAME,
 			  &phys, sizeof(phys));
 	if (err < 0)
 		goto out_pack;
 
+	err = fdt_setprop(root_fdt, off, KHO_SUB_TREE_SIZE_PROP_NAME,
+			  &size_u64, sizeof(size_u64));
+	if (err < 0)
+		goto out_pack;
+
 	WARN_ON_ONCE(kho_debugfs_blob_add(&kho_out.dbg, name, blob,
 					  size, false));
 
@@ -792,7 +798,7 @@ void kho_remove_subtree(void *blob)
 		const u64 *val;
 		int len;
 
-		val = fdt_getprop(root_fdt, off, KHO_FDT_SUB_TREE_PROP_NAME, &len);
+		val = fdt_getprop(root_fdt, off, KHO_SUB_TREE_PROP_NAME, &len);
 		if (!val || len != sizeof(phys_addr_t))
 			continue;
 
@@ -1297,13 +1303,14 @@ EXPORT_SYMBOL_GPL(is_kho_boot);
  * kho_retrieve_subtree - retrieve a preserved sub blob by its name.
  * @name: the name of the sub blob passed to kho_add_subtree().
  * @phys: if found, the physical address of the sub blob is stored in @phys.
+ * @size: if not NULL and found, the size of the sub blob is stored in @size.
  *
  * Retrieve a preserved sub blob named @name and store its physical
- * address in @phys.
+ * address in @phys and optionally its size in @size.
  *
  * Return: 0 on success, error code on failure
  */
-int kho_retrieve_subtree(const char *name, phys_addr_t *phys)
+int kho_retrieve_subtree(const char *name, phys_addr_t *phys, size_t *size)
 {
 	const void *fdt = kho_get_fdt();
 	const u64 *val;
@@ -1319,12 +1326,22 @@ int kho_retrieve_subtree(const char *name, phys_addr_t *phys)
 	if (offset < 0)
 		return -ENOENT;
 
-	val = fdt_getprop(fdt, offset, KHO_FDT_SUB_TREE_PROP_NAME, &len);
+	val = fdt_getprop(fdt, offset, KHO_SUB_TREE_PROP_NAME, &len);
 	if (!val || len != sizeof(*val))
 		return -EINVAL;
 
 	*phys = (phys_addr_t)*val;
 
+	val = fdt_getprop(fdt, offset, KHO_SUB_TREE_SIZE_PROP_NAME, &len);
+	if (!val || len != sizeof(*val)) {
+		pr_warn("broken KHO subnode '%s': missing or invalid blob-size property\n",
+			name);
+		return -EINVAL;
+	}
+
+	if (size)
+		*size = (size_t)*val;
+
 	return 0;
 }
 EXPORT_SYMBOL_GPL(kho_retrieve_subtree);
diff --git a/kernel/liveupdate/kexec_handover_debugfs.c b/kernel/liveupdate/kexec_handover_debugfs.c
index cab923e4f5c8..b416846810d7 100644
--- a/kernel/liveupdate/kexec_handover_debugfs.c
+++ b/kernel/liveupdate/kexec_handover_debugfs.c
@@ -125,7 +125,8 @@ __init void kho_in_debugfs_init(struct kho_debugfs *dbg, const void *fdt)
 		const u64 *fdt_phys;
 		void *sub_fdt;
 
-		fdt_phys = fdt_getprop(fdt, child, KHO_FDT_SUB_TREE_PROP_NAME, &len);
+		fdt_phys = fdt_getprop(fdt, child,
+					KHO_SUB_TREE_PROP_NAME, &len);
 		if (!fdt_phys)
 			continue;
 		if (len != sizeof(*fdt_phys)) {
diff --git a/kernel/liveupdate/luo_core.c b/kernel/liveupdate/luo_core.c
index 04d06a0906c0..48b25c9abeda 100644
--- a/kernel/liveupdate/luo_core.c
+++ b/kernel/liveupdate/luo_core.c
@@ -88,7 +88,7 @@ static int __init luo_early_startup(void)
 	}
 
 	/* Retrieve LUO subtree, and verify its format. */
-	err = kho_retrieve_subtree(LUO_FDT_KHO_ENTRY_NAME, &fdt_phys);
+	err = kho_retrieve_subtree(LUO_FDT_KHO_ENTRY_NAME, &fdt_phys, NULL);
 	if (err) {
 		if (err != -ENOENT) {
 			pr_err("failed to retrieve FDT '%s' from KHO: %pe\n",
diff --git a/lib/test_kho.c b/lib/test_kho.c
index 263182437315..aa6a0956bb8b 100644
--- a/lib/test_kho.c
+++ b/lib/test_kho.c
@@ -319,7 +319,7 @@ static int __init kho_test_init(void)
 	if (!kho_is_enabled())
 		return 0;
 
-	err = kho_retrieve_subtree(KHO_TEST_FDT, &fdt_phys);
+	err = kho_retrieve_subtree(KHO_TEST_FDT, &fdt_phys, NULL);
 	if (!err) {
 		err = kho_test_restore(fdt_phys);
 		if (err)
diff --git a/mm/memblock.c b/mm/memblock.c
index 91d4162eec63..a1c6dd0f6fad 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -2555,7 +2555,7 @@ static void *__init reserve_mem_kho_retrieve_fdt(void)
 	if (fdt)
 		return fdt;
 
-	err = kho_retrieve_subtree(MEMBLOCK_KHO_FDT, &fdt_phys);
+	err = kho_retrieve_subtree(MEMBLOCK_KHO_FDT, &fdt_phys, NULL);
 	if (err) {
 		if (err != -ENOENT)
 			pr_warn("failed to retrieve FDT '%s' from KHO: %d\n",