CC2538: NV read and write

I test it with the following red codes in SampleLight and everything works fine.

#define SSID_KEY 0x0403
#define PSWRD_KEY 0x0404
uint8 x1,x2,x3,x4,y1,y2,y3,y4;
uint8 ssid1[11]={0x78,0x78,0x78,0x78,0x78,0x78,0x78,0x78,0x78,0x78,0x78};
uint8 pswrd1[9]={0x87,0x87,0x87,0x87,0x87,0x87,0x87,0x87,0x87};
uint8 ssid2[11]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
uint8 pswrd2[9]={0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00};

void zclSampleLight_Init( byte task_id )
{
  zclSampleLight_TaskID = task_id;

  // Set destination address to indirect
  zclSampleLight_DstAddr.addrMode = (afAddrMode_t)AddrNotPresent;
  zclSampleLight_DstAddr.endPoint = 0;
  zclSampleLight_DstAddr.addr.shortAddr = 0;

  // This app is part of the Home Automation Profile
  zclHA_Init( &zclSampleLight_SimpleDesc );

  // Register the ZCL General Cluster Library callback functions
  zclGeneral_RegisterCmdCallbacks( SAMPLELIGHT_ENDPOINT, &zclSampleLight_CmdCallbacks );

  // Register the application's attribute list
  zcl_registerAttrList( SAMPLELIGHT_ENDPOINT, zclSampleLight_NumAttributes, zclSampleLight_Attrs );

  // Register the Application to receive the unprocessed Foundation command/response messages
  zcl_registerForMsg( zclSampleLight_TaskID );

#ifdef ZCL_DISCOVER
  // Register the application's command list
  zcl_registerCmdList( SAMPLELIGHT_ENDPOINT, zclCmdsArraySize, zclSampleLight_Cmds );
#endif

  // Register for all key events - This app will handle all key events
  RegisterForKeys( zclSampleLight_TaskID );

  // Register for a test endpoint
  afRegister( &sampleLight_TestEp );

#ifdef ZCL_EZMODE
  // Register EZ-Mode
  zcl_RegisterEZMode( &zclSampleLight_RegisterEZModeData );

  // Register with the ZDO to receive Match Descriptor Responses
  ZDO_RegisterForZDOMsg(task_id, Match_Desc_rsp);
#endif


#if (defined HAL_BOARD_ZLIGHT) || (defined HAL_PWM)
  HalTimer1Init( 0 );
  halTimer1SetChannelDuty( WHITE_LED, 0 );
  halTimer1SetChannelDuty( RED_LED, 0 );
  halTimer1SetChannelDuty( BLUE_LED, 0 );
  halTimer1SetChannelDuty( GREEN_LED, 0 );

  // find if we are already on a network from NV_RESTORE
  uint8 state;
  NLME_GetRequest( nwkNwkState, 0, &state );

  if ( state < NWK_ENDDEVICE )
  {
    // Start EZMode on Start up to avoid button press
    osal_start_timerEx( zclSampleLight_TaskID, SAMPLELIGHT_START_EZMODE_EVT, 500 );
  }
#if ZCL_LEVEL_CTRL
  zclSampleLight_DefaultMove();
#endif
#endif // #if (defined HAL_BOARD_ZLIGHT) || (defined HAL_PWM)

#ifdef ZCL_DIAGNOSTIC
  // Register the application's callback function to read/write attribute data.
  // This is only required when the attribute data format is unknown to ZCL.
  zcl_registerReadWriteCB( SAMPLELIGHT_ENDPOINT, zclDiagnostic_ReadWriteAttrCB, NULL );

  if ( zclDiagnostic_InitStats() == ZSuccess )
  {
    // Here the user could start the timer to save Diagnostics to NV
  }
#endif

#ifdef LCD_SUPPORTED
  HalLcdWriteString ( (char *)sDeviceName, HAL_LCD_LINE_3 );
#endif  // LCD_SUPPORTED

#ifdef ZGP_AUTO_TT
  zgpTranslationTable_RegisterEP ( &zclSampleLight_SimpleDesc );
#endif
  {
    x1=osal_nv_item_init(SSID_KEY,11, ssid1);
    x2=osal_nv_item_init(PSWRD_KEY, 9 , pswrd1);

    x3=osal_nv_write(SSID_KEY, 0,11, (void *)ssid1);
    x4=osal_nv_write(PSWRD_KEY, 0, 9, (void *)pswrd1);
    y3=osal_nv_read(SSID_KEY, 0, 11 , (void *)ssid2);
    y4=osal_nv_read(PSWRD_KEY, 0, 9 , (void *)pswrd2);
    y1=y2=y3=y4=0x00;

  }
}

This is the memory related issue.
Also, sometimes I face the problem that osal_mem_alloc is not able to allocate memory. It returns 00 to the pointer.
Do all these memory related problems have common issues?

I don't see Z-Stack uses memory allocate in osal_nv_xxxx related API.

It stores the binding table in NV.

I am using mem allocation just to give some content to my ssid1 and pswrd1 and it is successful in that. I can use this ssid1 and pswrd1 in further uses.