Malloc Array of structs, data in fields not saving properly

I have the following struct:

struct message {
    int id;
    int ack;
    int data_len;
    char *data;
    time_t timer;
} *messages, *temp;

I am allocating a chunk of memory to hold upto numMessages amount of these structs:

messages = malloc(sizeof(messages)*numMessages);

And then n messages can be added by calling the function ReadFromFile(int), with count initialized to 0

void readFromFile(int n) {

    char input_buff[4096];
    int size = sizeof(struct message);
    for (int i = 0; i < n; i++) {
        bzero(input_buff, sizeof(input_buff));
        int nread = fread(input_buff, 1 , msgSize, fp);

        if (nread > 0) { 
           printf("adding message: %d\n", count);

           temp = (struct message *) malloc (sizeof (struct message)); 
           temp->data_len = nread;
           temp->id = count; // set integer id
           temp->data = malloc( sizeof(char) * ( nread ));
           temp->ack = 0;

           memcpy(temp->data, input_buff, nread); 
           memcpy(&messages[count],temp,sizeof(temp));

           count++;
           free(temp);

        } 

        if (nread < sizeof(input_buff)) {
            if (feof(fp))
            printf("End of file\n");
            free(filename);
            close(fp);
            break;
        }

        if (ferror(fp)) {
            printf("Error reading\n");
            break;
        }
    }
}

HOWEVER, messages[count].data isn't being stored. However, if I swap the lines:

temp->data_len = nread; 

and

temp->data = malloc( sizeof(char) * ( nread ));

The data is properly stored, but now data_len isn't stored? What am I doing wrong? Besides the fact I'm sure that having a pointer temp and than coping the memory is redundant...

Thank you!