diff --git a/ChangeLog.d/fix-cipher-iv.txt b/ChangeLog.d/fix-cipher-iv.txt
new file mode 100644
index 0000000..e7af641
--- /dev/null
+++ b/ChangeLog.d/fix-cipher-iv.txt
@@ -0,0 +1,5 @@
+Security
+   * In psa_cipher_generate_iv() and psa_cipher_encrypt(), do not read back
+     from the output buffer. This fixes a potential policy bypass or decryption
+     oracle vulnerability if the output buffer is in memory that is shared with
+     an untrusted application.
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 5aed671..3bf470b 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3379,8 +3379,8 @@
                                      size_t *iv_length )
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
-
-    *iv_length = 0;
+    uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE];
+    size_t default_iv_length;
 
     if( operation->id == 0 )
     {
@@ -3394,28 +3394,38 @@
         goto exit;
     }
 
-    if( iv_size < operation->default_iv_length )
+    default_iv_length = operation->default_iv_length;
+    if( iv_size < default_iv_length )
     {
         status = PSA_ERROR_BUFFER_TOO_SMALL;
         goto exit;
     }
 
-    status = psa_generate_random( iv, operation->default_iv_length );
+    if( default_iv_length > PSA_CIPHER_IV_MAX_SIZE )
+    {
+        status = PSA_ERROR_GENERIC_ERROR;
+        goto exit;
+    }
+
+    status = psa_generate_random( local_iv, default_iv_length );
     if( status != PSA_SUCCESS )
         goto exit;
 
     status = psa_driver_wrapper_cipher_set_iv( operation,
-                                               iv,
-                                               operation->default_iv_length );
+                                               local_iv, default_iv_length );
 
 exit:
     if( status == PSA_SUCCESS )
     {
+        memcpy( iv, local_iv, default_iv_length );
+        *iv_length = default_iv_length;
         operation->iv_set = 1;
-        *iv_length = operation->default_iv_length;
     }
     else
+    {
+        *iv_length = 0;
         psa_cipher_abort( operation );
+    }
 
     return( status );
 }
@@ -3556,50 +3566,67 @@
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
     psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
-    psa_key_slot_t *slot;
-    psa_key_type_t key_type;
-    size_t iv_length;
-
-    *output_length = 0;
+    psa_key_slot_t *slot = NULL;
+    uint8_t local_iv[PSA_CIPHER_IV_MAX_SIZE];
+    size_t default_iv_length = 0;
 
     if( ! PSA_ALG_IS_CIPHER( alg ) )
-        return( PSA_ERROR_INVALID_ARGUMENT );
+    {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
 
     status = psa_get_and_lock_key_slot_with_policy( key, &slot,
                                                     PSA_KEY_USAGE_ENCRYPT,
                                                     alg );
     if( status != PSA_SUCCESS )
-        return( status );
+        goto exit;
 
     psa_key_attributes_t attributes = {
       .core = slot->attr
     };
 
-    key_type = slot->attr.type;
-    iv_length = PSA_CIPHER_IV_LENGTH( key_type, alg );
-
-    if( iv_length > 0 )
+    default_iv_length = PSA_CIPHER_IV_LENGTH( slot->attr.type, alg );
+    if( default_iv_length > PSA_CIPHER_IV_MAX_SIZE )
     {
-        if( output_size < iv_length )
+        status = PSA_ERROR_GENERIC_ERROR;
+        goto exit;
+    }
+
+    if( default_iv_length > 0 )
+    {
+        if( output_size < default_iv_length )
         {
             status = PSA_ERROR_BUFFER_TOO_SMALL;
             goto exit;
         }
 
-        status = psa_generate_random( output, iv_length );
+        status = psa_generate_random( local_iv, default_iv_length );
         if( status != PSA_SUCCESS )
             goto exit;
     }
 
     status = psa_driver_wrapper_cipher_encrypt(
         &attributes, slot->key.data, slot->key.bytes,
-        alg, input, input_length,
-        output, output_size, output_length );
+        alg, local_iv, default_iv_length, input, input_length,
+        output + default_iv_length, output_size - default_iv_length,
+        output_length );
 
 exit:
     unlock_status = psa_unlock_key_slot( slot );
+    if( status == PSA_SUCCESS )
+        status = unlock_status;
 
-    return( ( status == PSA_SUCCESS ) ? unlock_status : status );
+    if( status == PSA_SUCCESS )
+    {
+        if( default_iv_length > 0 )
+            memcpy( output, local_iv, default_iv_length );
+        *output_length += default_iv_length;
+    }
+    else
+        *output_length = 0;
+
+    return( status );
 }
 
 psa_status_t psa_cipher_decrypt( mbedtls_svc_key_id_t key,
@@ -3612,18 +3639,19 @@
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
     psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
-    psa_key_slot_t *slot;
-
-    *output_length = 0;
+    psa_key_slot_t *slot = NULL;
 
     if( ! PSA_ALG_IS_CIPHER( alg ) )
-        return( PSA_ERROR_INVALID_ARGUMENT );
+    {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
 
     status = psa_get_and_lock_key_slot_with_policy( key, &slot,
                                                     PSA_KEY_USAGE_DECRYPT,
                                                     alg );
     if( status != PSA_SUCCESS )
-        return( status );
+        goto exit;
 
     psa_key_attributes_t attributes = {
       .core = slot->attr
@@ -3642,8 +3670,13 @@
 
 exit:
     unlock_status = psa_unlock_key_slot( slot );
+    if( status == PSA_SUCCESS )
+        status = unlock_status;
 
-    return( ( status == PSA_SUCCESS ) ? unlock_status : status );
+    if( status != PSA_SUCCESS )
+        *output_length = 0;
+
+    return( status );
 }
 
 
diff --git a/library/psa_crypto_cipher.c b/library/psa_crypto_cipher.c
index 713c3d1..22f5363 100644
--- a/library/psa_crypto_cipher.c
+++ b/library/psa_crypto_cipher.c
@@ -472,6 +472,8 @@
                                     const uint8_t *key_buffer,
                                     size_t key_buffer_size,
                                     psa_algorithm_t alg,
+                                    const uint8_t *iv,
+                                    size_t iv_length,
                                     const uint8_t *input,
                                     size_t input_length,
                                     uint8_t *output,
@@ -480,38 +482,32 @@
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
     mbedtls_psa_cipher_operation_t operation = MBEDTLS_PSA_CIPHER_OPERATION_INIT;
-    size_t olength, accumulated_length;
+    size_t update_output_length, finish_output_length;
 
     status = cipher_encrypt_setup( &operation, attributes,
                                    key_buffer, key_buffer_size, alg );
     if( status != PSA_SUCCESS )
         goto exit;
 
-    accumulated_length = 0;
-    if( operation.iv_length > 0 )
+    if( iv_length > 0 )
     {
-        status = cipher_set_iv( &operation, output, operation.iv_length );
+        status = cipher_set_iv( &operation, iv, iv_length );
         if( status != PSA_SUCCESS )
             goto exit;
-
-        accumulated_length = operation.iv_length;
     }
 
     status = cipher_update( &operation, input, input_length,
-                            output + operation.iv_length,
-                            output_size - operation.iv_length,
-                            &olength );
+                            output, output_size, &update_output_length );
     if( status != PSA_SUCCESS )
         goto exit;
 
-    accumulated_length += olength;
-
-    status = cipher_finish( &operation, output + accumulated_length,
-                            output_size - accumulated_length, &olength );
+    status = cipher_finish( &operation, output + update_output_length,
+                            output_size - update_output_length,
+                            &finish_output_length );
     if( status != PSA_SUCCESS )
         goto exit;
 
-    *output_length = accumulated_length + olength;
+    *output_length = update_output_length + finish_output_length;
 
 exit:
     if( status == PSA_SUCCESS )
@@ -627,6 +623,8 @@
                                          const uint8_t *key_buffer,
                                          size_t key_buffer_size,
                                          psa_algorithm_t alg,
+                                         const uint8_t *iv,
+                                         size_t iv_length,
                                          const uint8_t *input,
                                          size_t input_length,
                                          uint8_t *output,
@@ -634,7 +632,7 @@
                                          size_t *output_length )
 {
     return( cipher_encrypt( attributes, key_buffer, key_buffer_size,
-                            alg, input, input_length,
+                            alg, iv, iv_length, input, input_length,
                             output, output_size, output_length ) );
 }
 
@@ -713,6 +711,8 @@
     const uint8_t *key_buffer,
     size_t key_buffer_size,
     psa_algorithm_t alg,
+    const uint8_t *iv,
+    size_t iv_length,
     const uint8_t *input,
     size_t input_length,
     uint8_t *output,
@@ -720,7 +720,7 @@
     size_t *output_length )
 {
     return( cipher_encrypt( attributes, key_buffer, key_buffer_size,
-                            alg, input, input_length,
+                            alg, iv, iv_length, input, input_length,
                             output, output_size, output_length ) );
 }
 
diff --git a/library/psa_crypto_cipher.h b/library/psa_crypto_cipher.h
index 5971e8d..76ff22a 100644
--- a/library/psa_crypto_cipher.h
+++ b/library/psa_crypto_cipher.h
@@ -213,16 +213,12 @@
  * \param[in] alg               The cipher algorithm to compute
  *                              (\c PSA_ALG_XXX value such that
  *                              #PSA_ALG_IS_CIPHER(\p alg) is true).
- * \param[in]  input            Buffer containing the message to encrypt.
- * \param[in]  input_length     Size of the \p input buffer in bytes.
+ * \param[in] iv                Buffer containing the IV for encryption. The
+ *                              IV has been generated by the core.
+ * \param[in] iv_length         Size of the \p iv in bytes.
+ * \param[in] input             Buffer containing the message to encrypt.
+ * \param[in] input_length      Size of the \p input buffer in bytes.
  * \param[in,out] output        Buffer where the output is to be written.
- *                              The core has generated and written the IV
- *                              at the beginning of this buffer before
- *                              this function is called. The size of the IV
- *                              is PSA_CIPHER_IV_LENGTH( key_type, alg ) where
- *                              \c key_type is the type of the key identified
- *                              by \p key and \p alg is the cipher algorithm
- *                              to compute.
  * \param[in]  output_size      Size of the \p output buffer in bytes.
  * \param[out] output_length    On success, the number of bytes that make up
  *                              the returned output. Initialized to zero
@@ -235,7 +231,7 @@
  * \retval #PSA_ERROR_BUFFER_TOO_SMALL
  *         The size of the \p output buffer is too small.
  * \retval #PSA_ERROR_INVALID_ARGUMENT
- *         The size of \p iv is not acceptable for the chosen algorithm,
+ *         The size \p iv_length is not acceptable for the chosen algorithm,
  *         or the chosen algorithm does not use an IV.
  *         The total input size passed to this operation is not valid for
  *         this particular algorithm. For example, the algorithm is a based
@@ -249,6 +245,8 @@
                                          const uint8_t *key_buffer,
                                          size_t key_buffer_size,
                                          psa_algorithm_t alg,
+                                         const uint8_t *iv,
+                                         size_t iv_length,
                                          const uint8_t *input,
                                          size_t input_length,
                                          uint8_t *output,
@@ -342,6 +340,8 @@
     const uint8_t *key_buffer,
     size_t key_buffer_size,
     psa_algorithm_t alg,
+    const uint8_t *iv,
+    size_t iv_length,
     const uint8_t *input,
     size_t input_length,
     uint8_t *output,
diff --git a/library/psa_crypto_driver_wrappers.c b/library/psa_crypto_driver_wrappers.c
index f7240ce..5fba955 100644
--- a/library/psa_crypto_driver_wrappers.c
+++ b/library/psa_crypto_driver_wrappers.c
@@ -740,6 +740,8 @@
     const uint8_t *key_buffer,
     size_t key_buffer_size,
     psa_algorithm_t alg,
+    const uint8_t *iv,
+    size_t iv_length,
     const uint8_t *input,
     size_t input_length,
     uint8_t *output,
@@ -761,6 +763,8 @@
                                                               key_buffer,
                                                               key_buffer_size,
                                                               alg,
+                                                              iv,
+                                                              iv_length,
                                                               input,
                                                               input_length,
                                                               output,
@@ -777,6 +781,8 @@
                                                 key_buffer,
                                                 key_buffer_size,
                                                 alg,
+                                                iv,
+                                                iv_length,
                                                 input,
                                                 input_length,
                                                 output,
@@ -794,6 +800,8 @@
                                                         key_buffer,
                                                         key_buffer_size,
                                                         alg,
+                                                        iv,
+                                                        iv_length,
                                                         input,
                                                         input_length,
                                                         output,
diff --git a/library/psa_crypto_driver_wrappers.h b/library/psa_crypto_driver_wrappers.h
index 38a6ee8..9eb08bc 100644
--- a/library/psa_crypto_driver_wrappers.h
+++ b/library/psa_crypto_driver_wrappers.h
@@ -102,6 +102,8 @@
     const uint8_t *key_buffer,
     size_t key_buffer_size,
     psa_algorithm_t alg,
+    const uint8_t *iv,
+    size_t iv_length,
     const uint8_t *input,
     size_t input_length,
     uint8_t *output,
diff --git a/tests/include/test/drivers/cipher.h b/tests/include/test/drivers/cipher.h
index 4fe5596..c1aa616 100644
--- a/tests/include/test/drivers/cipher.h
+++ b/tests/include/test/drivers/cipher.h
@@ -57,6 +57,7 @@
     const psa_key_attributes_t *attributes,
     const uint8_t *key, size_t key_length,
     psa_algorithm_t alg,
+    const uint8_t *iv, size_t iv_length,
     const uint8_t *input, size_t input_length,
     uint8_t *output, size_t output_size, size_t *output_length);
 
@@ -102,6 +103,7 @@
     const psa_key_attributes_t *attributes,
     const uint8_t *key, size_t key_length,
     psa_algorithm_t alg,
+    const uint8_t *iv, size_t iv_length,
     const uint8_t *input, size_t input_length,
     uint8_t *output, size_t output_size, size_t *output_length);
 
diff --git a/tests/src/drivers/test_driver_cipher.c b/tests/src/drivers/test_driver_cipher.c
index 6aca193..9e0dc30 100644
--- a/tests/src/drivers/test_driver_cipher.c
+++ b/tests/src/drivers/test_driver_cipher.c
@@ -44,6 +44,8 @@
     const uint8_t *key_buffer,
     size_t key_buffer_size,
     psa_algorithm_t alg,
+    const uint8_t *iv,
+    size_t iv_length,
     const uint8_t *input,
     size_t input_length,
     uint8_t *output,
@@ -68,11 +70,9 @@
     if( mbedtls_test_driver_cipher_hooks.forced_status != PSA_SUCCESS )
         return( mbedtls_test_driver_cipher_hooks.forced_status );
 
-    psa_generate_random( output, PSA_CIPHER_IV_LENGTH( attributes->core.type, alg ) );
-
     return( mbedtls_transparent_test_driver_cipher_encrypt(
                 attributes, key_buffer, key_buffer_size,
-                alg, input, input_length,
+                alg, iv, iv_length, input, input_length,
                 output, output_size, output_length ) );
 }
 
@@ -246,6 +246,7 @@
     const psa_key_attributes_t *attributes,
     const uint8_t *key, size_t key_length,
     psa_algorithm_t alg,
+    const uint8_t *iv, size_t iv_length,
     const uint8_t *input, size_t input_length,
     uint8_t *output, size_t output_size, size_t *output_length)
 {
@@ -253,6 +254,8 @@
     (void) key;
     (void) key_length;
     (void) alg;
+    (void) iv;
+    (void) iv_length;
     (void) input;
     (void) input_length;
     (void) output;
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 9ed1424..eb9458f 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -2600,6 +2600,9 @@
     mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
     psa_key_type_t key_type = key_type_arg;
     psa_algorithm_t alg = alg_arg;
+    psa_cipher_operation_t operation = PSA_CIPHER_OPERATION_INIT;
+    uint8_t iv[1] = { 0x5a };
+    size_t iv_length;
     unsigned char *output = NULL;
     size_t output_buffer_size = 0;
     size_t output_length = 0;
@@ -2617,6 +2620,14 @@
     PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
                                 &key ) );
 
+    PSA_ASSERT( psa_cipher_encrypt_setup( &operation, key, alg ) );
+    TEST_EQUAL( psa_cipher_set_iv( &operation, iv, sizeof( iv ) ),
+                PSA_ERROR_BAD_STATE );
+    PSA_ASSERT( psa_cipher_encrypt_setup( &operation, key, alg ) );
+    TEST_EQUAL( psa_cipher_generate_iv( &operation, iv, sizeof( iv ),
+                                        &iv_length ),
+                PSA_ERROR_BAD_STATE );
+
     PSA_ASSERT( psa_cipher_encrypt( key, alg, input->x, input->len, output,
                                     output_buffer_size, &output_length ) );
     TEST_ASSERT( output_length <=
diff --git a/tests/suites/test_suite_psa_crypto_driver_wrappers.function b/tests/suites/test_suite_psa_crypto_driver_wrappers.function
index 6d78ad5..74cc032 100644
--- a/tests/suites/test_suite_psa_crypto_driver_wrappers.function
+++ b/tests/suites/test_suite_psa_crypto_driver_wrappers.function
@@ -872,6 +872,39 @@
     PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
                                 &key ) );
 
+    /*
+     * Test encrypt failure
+     * First test that if we don't force a driver error, encryption is
+     * successfull, then force driver error.
+     */
+    status = psa_cipher_encrypt(
+        key, alg, input->x, input->len,
+        output, output_buffer_size, &function_output_length );
+    TEST_EQUAL( mbedtls_test_driver_cipher_hooks.hits, 1 );
+    TEST_EQUAL( status, PSA_SUCCESS );
+    mbedtls_test_driver_cipher_hooks.hits = 0;
+
+    mbedtls_test_driver_cipher_hooks.forced_status = PSA_ERROR_GENERIC_ERROR;
+    /* Set the output buffer in a given state. */
+    for( size_t i = 0; i < output_buffer_size; i++ )
+        output[i] = 0xa5;
+
+    status = psa_cipher_encrypt(
+        key, alg, input->x, input->len,
+        output, output_buffer_size, &function_output_length );
+    TEST_EQUAL( mbedtls_test_driver_cipher_hooks.hits, 1 );
+    TEST_EQUAL( status, PSA_ERROR_GENERIC_ERROR );
+    /*
+     * Check that the output buffer is still in the same state.
+     * This will fail if the output buffer is used by the core to pass the IV
+     * it generated to the driver (and is not restored).
+     */
+    for( size_t i = 0; i < output_buffer_size; i++ )
+    {
+        TEST_EQUAL( output[i], 0xa5 );
+    }
+    mbedtls_test_driver_cipher_hooks.hits = 0;
+
     /* Test setup call, encrypt */
     mbedtls_test_driver_cipher_hooks.forced_status = PSA_ERROR_GENERIC_ERROR;
     status = psa_cipher_encrypt_setup( &operation, key, alg );
@@ -923,10 +956,23 @@
     mbedtls_test_driver_cipher_hooks.hits = 0;
 
     mbedtls_test_driver_cipher_hooks.forced_status = PSA_ERROR_GENERIC_ERROR;
+    /* Set the output buffer in a given state. */
+    for( size_t i = 0; i < 16; i++ )
+        output[i] = 0xa5;
+
     status = psa_cipher_generate_iv( &operation, output, 16, &function_output_length );
     /* When generating the IV fails, it should call abort too */
     TEST_EQUAL( mbedtls_test_driver_cipher_hooks.hits, 2 );
     TEST_EQUAL( status, mbedtls_test_driver_cipher_hooks.forced_status );
+    /*
+     * Check that the output buffer is still in the same state.
+     * This will fail if the output buffer is used by the core to pass the IV
+     * it generated to the driver (and is not restored).
+     */
+    for( size_t i = 0; i < 16; i++ )
+    {
+        TEST_EQUAL( output[i], 0xa5 );
+    }
     /* Failure should prevent further operations from executing on the driver */
     mbedtls_test_driver_cipher_hooks.hits = 0;
     status = psa_cipher_update( &operation,