How to transmit the attribute data by using the application's callback function .

Hi  all：

          there is  a attribute which  was  set as NULL.

          I want to  transmit  the data of this attribute  by using the  application's callback function.

         1.  I  register the callback  function at the end of initial  function

              zcl_registerReadWriteCB( Test_ENDPOINT,&zcl_GetAttrFSUserIDsReadCB,NULL);

         2.   zcl_GetAttrFSUserIDsReadCB()  is  like that :

static ZStatus_t zcl_GetAttrFSUserIDsReadCB(uint16 clusterId, uint16 attrId, uint8 oper,uint8 *pValue, uint16 *pLen)
{    
  uint8 status;
   
  switch (oper)
  {
    case ZCL_OPER_READ:
          uint8 *temp = (uint8*)osal_mem_alloc(datalength+1); 
          temp[0]=datalength ;              
          for(uint8 i= 1; i<datalength+1; i++)          
          {
            temp[i]=i;
          } 
          osal_memcpy(pValue,temp,datalength +1); 
          osal_mem_free( temp );
    break;

    case ZCL_OPER_LEN:
          *pLen = datalength ;
          status = ZCL_STATUS_SUCCESS;
      break;
 }
}

PS:  datalength is dynamic, it will be changed.

     but   when  a  read attribute cmd coming , the devices  was  shut down.  it seems  memory leak...

     maybe  i  can't  osal_memcpy(pValue,temp,datalength +1) ,  but  i don't konw  why and  how to copy the array  to  pVaule.