diff --git a/ip/xfrm_state.c b/ip/xfrm_state.c
index a76be47..30a9aa3 100644
--- a/ip/xfrm_state.c
+++ b/ip/xfrm_state.c
@@ -368,13 +368,16 @@ static int xfrm_state_modify(int cmd, unsigned flags, int argc, char **argv)
 						struct xfrm_algo_auth auth;
 					} u;
 					char buf[XFRM_ALGO_KEY_BUF_SIZE];
-				} alg = {};
+				} *alg;
 				int len;
 				__u32 icvlen, trunclen;
 				char *name;
 				char *key;
 				char *buf;
 
+				alg = alloca (sizeof (*alg) + XFRM_ALGO_KEY_BUF_SIZE);
+				memset (alg, 0, sizeof (*alg) + XFRM_ALGO_KEY_BUF_SIZE);
+
 				switch (type) {
 				case XFRMA_ALG_AEAD:
 					if (aeadop)
@@ -412,8 +415,8 @@ static int xfrm_state_modify(int cmd, unsigned flags, int argc, char **argv)
 				NEXT_ARG();
 				key = *argv;
 
-				buf = alg.u.alg.alg_key;
-				len = sizeof(alg.u.alg);
+				buf = alg->u.alg.alg_key;
+				len = sizeof(alg->u.alg);
 
 				switch (type) {
 				case XFRMA_ALG_AEAD:
@@ -423,10 +426,10 @@ static int xfrm_state_modify(int cmd, unsigned flags, int argc, char **argv)
 					if (get_u32(&icvlen, *argv, 0))
 						invarg("\"aead\" ICV length is invalid",
 						       *argv);
-					alg.u.aead.alg_icv_len = icvlen;
+					alg->u.aead.alg_icv_len = icvlen;
 
-					buf = alg.u.aead.alg_key;
-					len = sizeof(alg.u.aead);
+					buf = alg->u.aead.alg_key;
+					len = sizeof(alg->u.aead);
 					break;
 				case XFRMA_ALG_AUTH_TRUNC:
 					if (!NEXT_ARG_OK())
@@ -435,19 +438,19 @@ static int xfrm_state_modify(int cmd, unsigned flags, int argc, char **argv)
 					if (get_u32(&trunclen, *argv, 0))
 						invarg("\"auth\" trunc length is invalid",
 						       *argv);
-					alg.u.auth.alg_trunc_len = trunclen;
+					alg->u.auth.alg_trunc_len = trunclen;
 
-					buf = alg.u.auth.alg_key;
-					len = sizeof(alg.u.auth);
+					buf = alg->u.auth.alg_key;
+					len = sizeof(alg->u.auth);
 					break;
 				}
 
-				xfrm_algo_parse((void *)&alg, type, name, key,
-						buf, sizeof(alg.buf));
-				len += alg.u.alg.alg_key_len;
+				xfrm_algo_parse((void *)alg, type, name, key,
+						buf, sizeof(alg->buf));
+				len += alg->u.alg.alg_key_len;
 
 				addattr_l(&req.n, sizeof(req.buf), type,
-					  (void *)&alg, len);
+					  (void *)alg, len);
 				break;
 			}
 			default: