diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index b40c3b0def920d88c997fb3291318dd634451466..e5cbf91aadfe258d36e2fb3b6cb2632eb569fc10 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -138,12 +138,12 @@ static int setup_dtb(struct kimage *image,
 
 	/* add rng-seed */
 	if (rng_is_initialized()) {
-		u8 rng_seed[RNG_SEED_SIZE];
-		get_random_bytes(rng_seed, RNG_SEED_SIZE);
-		ret = fdt_setprop(dtb, off, FDT_PROP_RNG_SEED, rng_seed,
-				RNG_SEED_SIZE);
+		void *rng_seed;
+		ret = fdt_setprop_placeholder(dtb, off, FDT_PROP_RNG_SEED,
+				RNG_SEED_SIZE, &rng_seed);
 		if (ret)
 			goto out;
+		get_random_bytes(rng_seed, RNG_SEED_SIZE);
 	} else {
 		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
 				FDT_PROP_RNG_SEED);