From 800627f054959aac0dd3527495ee3fad0137600a Mon Sep 17 00:00:00 2001
From: Jihwan Park <jihwp@amazon.com>
Date: Mon, 3 Jul 2023 08:51:47 +0200
Subject: [PATCH] core: crypto_bignum_free(): add indirection and set pointer
 to NULL

To prevent human mistake, crypto_bignum_free() sets the location of the
bignum pointer to NULL after freeing it.

Signed-off-by: Jihwan Park <jihwp@amazon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Reviewed-by: Joakim Bech <joakim.bech@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@foss.st.com>

CVE: CVE-2023-41325
Upstream-Status: Backport
Signed-off-by: Ross Burton <ross.burton@arm.com>
---
 core/crypto/crypto.c                        |  4 +--
 core/drivers/crypto/caam/acipher/caam_dh.c  |  8 ++---
 core/drivers/crypto/caam/acipher/caam_dsa.c | 14 ++++----
 core/drivers/crypto/caam/acipher/caam_ecc.c | 10 +++---
 core/drivers/crypto/caam/acipher/caam_rsa.c | 24 ++++++-------
 core/drivers/crypto/se050/core/ecc.c        | 14 ++++----
 core/drivers/crypto/se050/core/rsa.c        | 38 ++++++++++-----------
 core/drivers/crypto/versal/ecc.c            |  6 ++--
 core/include/crypto/crypto.h                |  2 +-
 core/lib/libtomcrypt/dh.c                   |  8 ++---
 core/lib/libtomcrypt/dsa.c                  | 14 ++++----
 core/lib/libtomcrypt/ecc.c                  | 10 +++---
 core/lib/libtomcrypt/mpi_desc.c             |  9 +++--
 core/lib/libtomcrypt/rsa.c                  | 22 ++++++------
 core/tee/tee_svc_cryp.c                     |  7 ++--
 lib/libmbedtls/core/bignum.c                |  9 +++--
 lib/libmbedtls/core/dh.c                    |  8 ++---
 lib/libmbedtls/core/ecc.c                   | 10 +++---
 lib/libmbedtls/core/rsa.c                   | 22 ++++++------
 19 files changed, 122 insertions(+), 117 deletions(-)

diff --git a/core/crypto/crypto.c b/core/crypto/crypto.c
index 9f7d35097..60cb89a31 100644
--- a/core/crypto/crypto.c
+++ b/core/crypto/crypto.c
@@ -498,9 +498,9 @@ void crypto_bignum_copy(struct bignum *to __unused,
 	bignum_cant_happen();
 }
 
-void crypto_bignum_free(struct bignum *a)
+void crypto_bignum_free(struct bignum **a)
 {
-	if (a)
+	if (a && *a)
 		panic();
 }
 
diff --git a/core/drivers/crypto/caam/acipher/caam_dh.c b/core/drivers/crypto/caam/acipher/caam_dh.c
index 6131ff0ef..35fc44541 100644
--- a/core/drivers/crypto/caam/acipher/caam_dh.c
+++ b/core/drivers/crypto/caam/acipher/caam_dh.c
@@ -195,10 +195,10 @@ static TEE_Result do_allocate_keypair(struct dh_keypair *key, size_t size_bits)
 err:
 	DH_TRACE("Allocation error");
 
-	crypto_bignum_free(key->g);
-	crypto_bignum_free(key->p);
-	crypto_bignum_free(key->x);
-	crypto_bignum_free(key->y);
+	crypto_bignum_free(&key->g);
+	crypto_bignum_free(&key->p);
+	crypto_bignum_free(&key->x);
+	crypto_bignum_free(&key->y);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
diff --git a/core/drivers/crypto/caam/acipher/caam_dsa.c b/core/drivers/crypto/caam/acipher/caam_dsa.c
index 2696f0b3c..d60bb8e89 100644
--- a/core/drivers/crypto/caam/acipher/caam_dsa.c
+++ b/core/drivers/crypto/caam/acipher/caam_dsa.c
@@ -309,10 +309,10 @@ static TEE_Result do_allocate_keypair(struct dsa_keypair *key, size_t l_bits,
 err:
 	DSA_TRACE("Allocation error");
 
-	crypto_bignum_free(key->g);
-	crypto_bignum_free(key->p);
-	crypto_bignum_free(key->q);
-	crypto_bignum_free(key->x);
+	crypto_bignum_free(&key->g);
+	crypto_bignum_free(&key->p);
+	crypto_bignum_free(&key->q);
+	crypto_bignum_free(&key->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -358,9 +358,9 @@ static TEE_Result do_allocate_publickey(struct dsa_public_key *key,
 err:
 	DSA_TRACE("Allocation error");
 
-	crypto_bignum_free(key->g);
-	crypto_bignum_free(key->p);
-	crypto_bignum_free(key->q);
+	crypto_bignum_free(&key->g);
+	crypto_bignum_free(&key->p);
+	crypto_bignum_free(&key->q);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
diff --git a/core/drivers/crypto/caam/acipher/caam_ecc.c b/core/drivers/crypto/caam/acipher/caam_ecc.c
index 90e87c20a..6b12b6cbe 100644
--- a/core/drivers/crypto/caam/acipher/caam_ecc.c
+++ b/core/drivers/crypto/caam/acipher/caam_ecc.c
@@ -169,8 +169,8 @@ static TEE_Result do_allocate_keypair(struct ecc_keypair *key, size_t size_bits)
 err:
 	ECC_TRACE("Allocation error");
 
-	crypto_bignum_free(key->d);
-	crypto_bignum_free(key->x);
+	crypto_bignum_free(&key->d);
+	crypto_bignum_free(&key->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -204,7 +204,7 @@ static TEE_Result do_allocate_publickey(struct ecc_public_key *key,
 err:
 	ECC_TRACE("Allocation error");
 
-	crypto_bignum_free(key->x);
+	crypto_bignum_free(&key->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -216,8 +216,8 @@ err:
  */
 static void do_free_publickey(struct ecc_public_key *key)
 {
-	crypto_bignum_free(key->x);
-	crypto_bignum_free(key->y);
+	crypto_bignum_free(&key->x);
+	crypto_bignum_free(&key->y);
 }
 
 /*
diff --git a/core/drivers/crypto/caam/acipher/caam_rsa.c b/core/drivers/crypto/caam/acipher/caam_rsa.c
index e860c641c..b59ab0b6e 100644
--- a/core/drivers/crypto/caam/acipher/caam_rsa.c
+++ b/core/drivers/crypto/caam/acipher/caam_rsa.c
@@ -86,14 +86,14 @@ static uint8_t caam_era;
  */
 static void do_free_keypair(struct rsa_keypair *key)
 {
-	crypto_bignum_free(key->e);
-	crypto_bignum_free(key->d);
-	crypto_bignum_free(key->n);
-	crypto_bignum_free(key->p);
-	crypto_bignum_free(key->q);
-	crypto_bignum_free(key->qp);
-	crypto_bignum_free(key->dp);
-	crypto_bignum_free(key->dq);
+	crypto_bignum_free(&key->e);
+	crypto_bignum_free(&key->d);
+	crypto_bignum_free(&key->n);
+	crypto_bignum_free(&key->p);
+	crypto_bignum_free(&key->q);
+	crypto_bignum_free(&key->qp);
+	crypto_bignum_free(&key->dp);
+	crypto_bignum_free(&key->dq);
 }
 
 /*
@@ -435,8 +435,8 @@ static TEE_Result do_allocate_publickey(struct rsa_public_key *key,
 err_alloc_publickey:
 	RSA_TRACE("Allocation error");
 
-	crypto_bignum_free(key->e);
-	crypto_bignum_free(key->n);
+	crypto_bignum_free(&key->e);
+	crypto_bignum_free(&key->n);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -448,8 +448,8 @@ err_alloc_publickey:
  */
 static void do_free_publickey(struct rsa_public_key *key)
 {
-	crypto_bignum_free(key->e);
-	crypto_bignum_free(key->n);
+	crypto_bignum_free(&key->e);
+	crypto_bignum_free(&key->n);
 }
 
 /*
diff --git a/core/drivers/crypto/se050/core/ecc.c b/core/drivers/crypto/se050/core/ecc.c
index d74334760..52f82c69d 100644
--- a/core/drivers/crypto/se050/core/ecc.c
+++ b/core/drivers/crypto/se050/core/ecc.c
@@ -752,9 +752,9 @@ static TEE_Result do_alloc_keypair(struct ecc_keypair *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->x);
-	crypto_bignum_free(s->y);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->x);
+	crypto_bignum_free(&s->y);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
@@ -768,8 +768,8 @@ static TEE_Result do_alloc_publickey(struct ecc_public_key *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->x);
-	crypto_bignum_free(s->y);
+	crypto_bignum_free(&s->x);
+	crypto_bignum_free(&s->y);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
@@ -778,8 +778,8 @@ static void do_free_publickey(struct ecc_public_key *s)
 	if (!s)
 		return;
 
-	crypto_bignum_free(s->x);
-	crypto_bignum_free(s->y);
+	crypto_bignum_free(&s->x);
+	crypto_bignum_free(&s->y);
 }
 
 static struct drvcrypt_ecc driver_ecc = {
diff --git a/core/drivers/crypto/se050/core/rsa.c b/core/drivers/crypto/se050/core/rsa.c
index 815abb3cd..475d2b99a 100644
--- a/core/drivers/crypto/se050/core/rsa.c
+++ b/core/drivers/crypto/se050/core/rsa.c
@@ -537,14 +537,14 @@ static TEE_Result do_alloc_keypair(struct rsa_keypair *s,
 
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->e);
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->n);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->q);
-	crypto_bignum_free(s->qp);
-	crypto_bignum_free(s->dp);
-	crypto_bignum_free(s->dq);
+	crypto_bignum_free(&s->e);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->n);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->q);
+	crypto_bignum_free(&s->qp);
+	crypto_bignum_free(&s->dp);
+	crypto_bignum_free(&s->dq);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -556,7 +556,7 @@ static TEE_Result do_alloc_publickey(struct rsa_public_key *s,
 	if (!bn_alloc_max(&s->e))
 		return TEE_ERROR_OUT_OF_MEMORY;
 	if (!bn_alloc_max(&s->n)) {
-		crypto_bignum_free(s->e);
+		crypto_bignum_free(&s->e);
 		return TEE_ERROR_OUT_OF_MEMORY;
 	}
 
@@ -566,8 +566,8 @@ static TEE_Result do_alloc_publickey(struct rsa_public_key *s,
 static void do_free_publickey(struct rsa_public_key *s)
 {
 	if (s) {
-		crypto_bignum_free(s->n);
-		crypto_bignum_free(s->e);
+		crypto_bignum_free(&s->n);
+		crypto_bignum_free(&s->e);
 	}
 }
 
@@ -587,14 +587,14 @@ static void do_free_keypair(struct rsa_keypair *s)
 			sss_se05x_key_store_erase_key(se050_kstore, &k_object);
 	}
 
-	crypto_bignum_free(s->e);
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->n);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->q);
-	crypto_bignum_free(s->qp);
-	crypto_bignum_free(s->dp);
-	crypto_bignum_free(s->dq);
+	crypto_bignum_free(&s->e);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->n);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->q);
+	crypto_bignum_free(&s->qp);
+	crypto_bignum_free(&s->dp);
+	crypto_bignum_free(&s->dq);
 }
 
 static TEE_Result do_gen_keypair(struct rsa_keypair *key, size_t kb)
diff --git a/core/drivers/crypto/versal/ecc.c b/core/drivers/crypto/versal/ecc.c
index 3d5454509..18ec4f78d 100644
--- a/core/drivers/crypto/versal/ecc.c
+++ b/core/drivers/crypto/versal/ecc.c
@@ -284,9 +284,9 @@ static TEE_Result sign(uint32_t algo, struct ecc_keypair *key,
 
 	versal_mbox_alloc(bytes, NULL, &k);
 	crypto_bignum_bn2bin_eswap(key->curve, ephemeral.d, k.buf);
-	crypto_bignum_free(ephemeral.d);
-	crypto_bignum_free(ephemeral.x);
-	crypto_bignum_free(ephemeral.y);
+	crypto_bignum_free(&ephemeral.d);
+	crypto_bignum_free(&ephemeral.x);
+	crypto_bignum_free(&ephemeral.y);
 
 	/* Private key*/
 	versal_mbox_alloc(bytes, NULL, &d);
diff --git a/core/include/crypto/crypto.h b/core/include/crypto/crypto.h
index 71a287ec6..0e6c139ce 100644
--- a/core/include/crypto/crypto.h
+++ b/core/include/crypto/crypto.h
@@ -98,7 +98,7 @@ size_t crypto_bignum_num_bytes(struct bignum *a);
 size_t crypto_bignum_num_bits(struct bignum *a);
 void crypto_bignum_bn2bin(const struct bignum *from, uint8_t *to);
 void crypto_bignum_copy(struct bignum *to, const struct bignum *from);
-void crypto_bignum_free(struct bignum *a);
+void crypto_bignum_free(struct bignum **a);
 void crypto_bignum_clear(struct bignum *a);
 
 /* return -1 if a<b, 0 if a==b, +1 if a>b */
diff --git a/core/lib/libtomcrypt/dh.c b/core/lib/libtomcrypt/dh.c
index 4eb9916f2..b1d0a4d00 100644
--- a/core/lib/libtomcrypt/dh.c
+++ b/core/lib/libtomcrypt/dh.c
@@ -28,10 +28,10 @@ TEE_Result crypto_acipher_alloc_dh_keypair(struct dh_keypair *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->g);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->y);
-	crypto_bignum_free(s->x);
+	crypto_bignum_free(&s->g);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->y);
+	crypto_bignum_free(&s->x);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
diff --git a/core/lib/libtomcrypt/dsa.c b/core/lib/libtomcrypt/dsa.c
index a2dc720ed..d6243c469 100644
--- a/core/lib/libtomcrypt/dsa.c
+++ b/core/lib/libtomcrypt/dsa.c
@@ -30,10 +30,10 @@ TEE_Result crypto_acipher_alloc_dsa_keypair(struct dsa_keypair *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->g);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->q);
-	crypto_bignum_free(s->y);
+	crypto_bignum_free(&s->g);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->q);
+	crypto_bignum_free(&s->y);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
@@ -52,9 +52,9 @@ TEE_Result crypto_acipher_alloc_dsa_public_key(struct dsa_public_key *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->g);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->q);
+	crypto_bignum_free(&s->g);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->q);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
diff --git a/core/lib/libtomcrypt/ecc.c b/core/lib/libtomcrypt/ecc.c
index 938378247..fa645e17a 100644
--- a/core/lib/libtomcrypt/ecc.c
+++ b/core/lib/libtomcrypt/ecc.c
@@ -18,8 +18,8 @@ static void _ltc_ecc_free_public_key(struct ecc_public_key *s)
 	if (!s)
 		return;
 
-	crypto_bignum_free(s->x);
-	crypto_bignum_free(s->y);
+	crypto_bignum_free(&s->x);
+	crypto_bignum_free(&s->y);
 }
 
 /*
@@ -465,8 +465,8 @@ TEE_Result crypto_asym_alloc_ecc_keypair(struct ecc_keypair *s,
 err:
 	s->ops = NULL;
 
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->x);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -541,7 +541,7 @@ TEE_Result crypto_asym_alloc_ecc_public_key(struct ecc_public_key *s,
 err:
 	s->ops = NULL;
 
-	crypto_bignum_free(s->x);
+	crypto_bignum_free(&s->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
diff --git a/core/lib/libtomcrypt/mpi_desc.c b/core/lib/libtomcrypt/mpi_desc.c
index 235fbe630..ff8dd13c7 100644
--- a/core/lib/libtomcrypt/mpi_desc.c
+++ b/core/lib/libtomcrypt/mpi_desc.c
@@ -763,10 +763,13 @@ struct bignum *crypto_bignum_allocate(size_t size_bits)
 	return (struct bignum *)bn;
 }
 
-void crypto_bignum_free(struct bignum *s)
+void crypto_bignum_free(struct bignum **s)
 {
-	mbedtls_mpi_free((mbedtls_mpi *)s);
-	free(s);
+	assert(s);
+
+	mbedtls_mpi_free((mbedtls_mpi *)*s);
+	free(*s);
+	*s = NULL;
 }
 
 void crypto_bignum_clear(struct bignum *s)
diff --git a/core/lib/libtomcrypt/rsa.c b/core/lib/libtomcrypt/rsa.c
index 8d0443f36..13ed23934 100644
--- a/core/lib/libtomcrypt/rsa.c
+++ b/core/lib/libtomcrypt/rsa.c
@@ -131,7 +131,7 @@ TEE_Result sw_crypto_acipher_alloc_rsa_public_key(struct rsa_public_key *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->e);
+	crypto_bignum_free(&s->e);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
@@ -143,8 +143,8 @@ void sw_crypto_acipher_free_rsa_public_key(struct rsa_public_key *s)
 {
 	if (!s)
 		return;
-	crypto_bignum_free(s->n);
-	crypto_bignum_free(s->e);
+	crypto_bignum_free(&s->n);
+	crypto_bignum_free(&s->e);
 }
 
 
@@ -155,14 +155,14 @@ void sw_crypto_acipher_free_rsa_keypair(struct rsa_keypair *s)
 {
 	if (!s)
 		return;
-	crypto_bignum_free(s->e);
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->n);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->q);
-	crypto_bignum_free(s->qp);
-	crypto_bignum_free(s->dp);
-	crypto_bignum_free(s->dq);
+	crypto_bignum_free(&s->e);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->n);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->q);
+	crypto_bignum_free(&s->qp);
+	crypto_bignum_free(&s->dp);
+	crypto_bignum_free(&s->dq);
 }
 
 TEE_Result crypto_acipher_gen_rsa_key(struct rsa_keypair *key,
diff --git a/core/tee/tee_svc_cryp.c b/core/tee/tee_svc_cryp.c
index 534e5ac39..880809753 100644
--- a/core/tee/tee_svc_cryp.c
+++ b/core/tee/tee_svc_cryp.c
@@ -869,8 +869,7 @@ static void op_attr_bignum_free(void *attr)
 {
 	struct bignum **bn = attr;
 
-	crypto_bignum_free(*bn);
-	*bn = NULL;
+	crypto_bignum_free(bn);
 }
 
 static TEE_Result op_attr_value_from_user(void *attr, const void *buffer,
@@ -3445,8 +3444,8 @@ TEE_Result syscall_cryp_derive_key(unsigned long state,
 		} else {
 			res = TEE_ERROR_OUT_OF_MEMORY;
 		}
-		crypto_bignum_free(pub);
-		crypto_bignum_free(ss);
+		crypto_bignum_free(&pub);
+		crypto_bignum_free(&ss);
 	} else if (TEE_ALG_GET_MAIN_ALG(cs->algo) == TEE_MAIN_ALGO_ECDH) {
 		struct ecc_public_key key_public;
 		uint8_t *pt_secret;
diff --git a/lib/libmbedtls/core/bignum.c b/lib/libmbedtls/core/bignum.c
index 61f6c5c60..dea30f61a 100644
--- a/lib/libmbedtls/core/bignum.c
+++ b/lib/libmbedtls/core/bignum.c
@@ -87,10 +87,13 @@ struct bignum *crypto_bignum_allocate(size_t size_bits)
 	return (struct bignum *)bn;
 }
 
-void crypto_bignum_free(struct bignum *s)
+void crypto_bignum_free(struct bignum **s)
 {
-	mbedtls_mpi_free((mbedtls_mpi *)s);
-	free(s);
+	assert(s);
+
+	mbedtls_mpi_free((mbedtls_mpi *)*s);
+	free(*s);
+	*s = NULL;
 }
 
 void crypto_bignum_clear(struct bignum *s)
diff --git a/lib/libmbedtls/core/dh.c b/lib/libmbedtls/core/dh.c
index b3415aaa7..e95aa1495 100644
--- a/lib/libmbedtls/core/dh.c
+++ b/lib/libmbedtls/core/dh.c
@@ -35,10 +35,10 @@ TEE_Result crypto_acipher_alloc_dh_keypair(struct dh_keypair *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->g);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->y);
-	crypto_bignum_free(s->x);
+	crypto_bignum_free(&s->g);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->y);
+	crypto_bignum_free(&s->x);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
diff --git a/lib/libmbedtls/core/ecc.c b/lib/libmbedtls/core/ecc.c
index fd4a51b9d..46cd9fd1c 100644
--- a/lib/libmbedtls/core/ecc.c
+++ b/lib/libmbedtls/core/ecc.c
@@ -40,8 +40,8 @@ static void ecc_free_public_key(struct ecc_public_key *s)
 	if (!s)
 		return;
 
-	crypto_bignum_free(s->x);
-	crypto_bignum_free(s->y);
+	crypto_bignum_free(&s->x);
+	crypto_bignum_free(&s->y);
 }
 
 /*
@@ -484,8 +484,8 @@ TEE_Result crypto_asym_alloc_ecc_keypair(struct ecc_keypair *s,
 	return TEE_SUCCESS;
 
 err:
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->x);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
@@ -581,7 +581,7 @@ TEE_Result crypto_asym_alloc_ecc_public_key(struct ecc_public_key *s,
 	return TEE_SUCCESS;
 
 err:
-	crypto_bignum_free(s->x);
+	crypto_bignum_free(&s->x);
 
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
diff --git a/lib/libmbedtls/core/rsa.c b/lib/libmbedtls/core/rsa.c
index c3b5be509..a8aeb2c04 100644
--- a/lib/libmbedtls/core/rsa.c
+++ b/lib/libmbedtls/core/rsa.c
@@ -183,7 +183,7 @@ TEE_Result sw_crypto_acipher_alloc_rsa_public_key(struct rsa_public_key *s,
 		goto err;
 	return TEE_SUCCESS;
 err:
-	crypto_bignum_free(s->e);
+	crypto_bignum_free(&s->e);
 	return TEE_ERROR_OUT_OF_MEMORY;
 }
 
@@ -194,8 +194,8 @@ void sw_crypto_acipher_free_rsa_public_key(struct rsa_public_key *s)
 {
 	if (!s)
 		return;
-	crypto_bignum_free(s->n);
-	crypto_bignum_free(s->e);
+	crypto_bignum_free(&s->n);
+	crypto_bignum_free(&s->e);
 }
 
 void crypto_acipher_free_rsa_keypair(struct rsa_keypair *s)
@@ -205,14 +205,14 @@ void sw_crypto_acipher_free_rsa_keypair(struct rsa_keypair *s)
 {
 	if (!s)
 		return;
-	crypto_bignum_free(s->e);
-	crypto_bignum_free(s->d);
-	crypto_bignum_free(s->n);
-	crypto_bignum_free(s->p);
-	crypto_bignum_free(s->q);
-	crypto_bignum_free(s->qp);
-	crypto_bignum_free(s->dp);
-	crypto_bignum_free(s->dq);
+	crypto_bignum_free(&s->e);
+	crypto_bignum_free(&s->d);
+	crypto_bignum_free(&s->n);
+	crypto_bignum_free(&s->p);
+	crypto_bignum_free(&s->q);
+	crypto_bignum_free(&s->qp);
+	crypto_bignum_free(&s->dp);
+	crypto_bignum_free(&s->dq);
 }
 
 TEE_Result crypto_acipher_gen_rsa_key(struct rsa_keypair *key,
-- 
2.34.1