fix(tests): correct the flash write length for NVS encrypted test

Write only till the embedded file size in the NVS partition. Earlier
the length was kept as the whole partition size and it could result
in accessing embedded rodata beyond the MMU mapped range.

Author: mahavirj

components/nvs_flash/test_apps/main/test_nvs.c

@@ -1,11 +1,12 @@
 /*
- * SPDX-FileCopyrightText: 2016-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2016-2024 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/param.h>
 
 #include <ctype.h>
 #include <errno.h>
@@ -587,6 +588,7 @@ TEST_CASE("test nvs apis for nvs partition generator utility with encryption ena
     extern const char nvs_key_start[] asm("_binary_encryption_keys_bin_start");
     extern const char nvs_key_end[]   asm("_binary_encryption_keys_bin_end");
     extern const char nvs_data_sch0_start[] asm("_binary_partition_encrypted_bin_start");
+    extern const char nvs_data_sch0_end[] asm("_binary_partition_encrypted_bin_end");
 
     const esp_partition_t* key_part = esp_partition_find_first(
             ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_NVS_KEYS, NULL);
@@ -600,15 +602,24 @@ TEST_CASE("test nvs apis for nvs partition generator utility with encryption ena
         ESP_ERROR_CHECK( esp_partition_write(key_part, i, nvs_key_start + i, SPI_FLASH_SEC_SIZE) );
     }
 
-    for (int i = 0; i < nvs_part->size; i+= SPI_FLASH_SEC_SIZE) {
+    const int content_size = nvs_data_sch0_end - nvs_data_sch0_start - 1;
+    TEST_ASSERT_TRUE((content_size % SPI_FLASH_SEC_SIZE) == 0);
+
+    const int size_to_write = MIN(content_size, nvs_part->size);
+    for (int i = 0; i < size_to_write; i+= SPI_FLASH_SEC_SIZE) {
         ESP_ERROR_CHECK( esp_partition_write(nvs_part, i, nvs_data_sch0_start + i, SPI_FLASH_SEC_SIZE) );
     }
 
     err = nvs_flash_read_security_cfg(key_part, &xts_cfg);
 #elif CONFIG_NVS_SEC_KEY_PROTECT_USING_HMAC
     extern const char nvs_data_sch1_start[]    asm("_binary_partition_encrypted_hmac_bin_start");
+    extern const char nvs_data_sch1_end[]    asm("_binary_partition_encrypted_hmac_bin_end");
+
+    const int content_size = nvs_data_sch1_end - nvs_data_sch1_start - 1;
+    TEST_ASSERT_TRUE((content_size % SPI_FLASH_SEC_SIZE) == 0);
 
-    for (int i = 0; i < nvs_part->size; i+= SPI_FLASH_SEC_SIZE) {
+    const int size_to_write = MIN(content_size, nvs_part->size);
+    for (int i = 0; i < size_to_write; i+= SPI_FLASH_SEC_SIZE) {
         ESP_ERROR_CHECK( esp_partition_write(nvs_part, i, nvs_data_sch1_start + i, SPI_FLASH_SEC_SIZE) );
     }