diff --git a/crypto/adiantum.c b/crypto/adiantum.c
index a6bca877c3c7..edd53c793fda 100644
--- a/crypto/adiantum.c
+++ b/crypto/adiantum.c
@@ -310,6 +310,7 @@ static int adiantum_finish(struct skcipher_request *req)
 			return err;
 		}
 		le128_sub(&rctx->rbuf.bignum, &rctx->rbuf.bignum, &digest);
+		memset(&rctx->rbuf.bignum, 0, sizeof(rctx->rbuf.bignum));
 		memcpy(virt + bulk_len, &rctx->rbuf.bignum, sizeof(le128));
 		flush_dcache_page(page);
 		kunmap_local(virt);
@@ -370,6 +371,7 @@ static int adiantum_crypt(struct skcipher_request *req, bool enc)
 	} else {
 		/* Slow path that works for any source scatterlist */
 		err = adiantum_hash_message(req, src, src_nents, &digest);
+		memset(&rctx->rbuf.bignum, 0, sizeof(rctx->rbuf.bignum));
 		scatterwalk_map_and_copy(&rctx->rbuf.bignum, src,
 					 bulk_len, sizeof(le128), 0);
 	}