static void getRDB(void) {
    int s = context->fd;
    int fd;
    unsigned long long payload = sendSync(s);
    char buf[4096];

    fprintf(stderr,"SYNC sent to master, writing %llu bytes to '%s'\n",
        payload, config.rdb_filename);

    /* Write to file. */
    if (!strcmp(config.rdb_filename,"-")) {
        fd = STDOUT_FILENO;
    } else {
        fd = open(config.rdb_filename, O_CREAT|O_WRONLY, 0644);
        if (fd == -1) {
            fprintf(stderr, "Error opening '%s': %s\n", config.rdb_filename,
                strerror(errno));
            exit(1);
        }
    }

    while(payload) {
        ssize_t nread, nwritten;

        nread = read(s,buf,(payload > sizeof(buf)) ? sizeof(buf) : payload);
        if (nread <= 0) {
            fprintf(stderr,"I/O Error reading RDB payload from socket\n");
            exit(1);
        }
        nwritten = write(fd, buf, nread);
        if (nwritten != nread) {
            fprintf(stderr,"Error writing data to file: %s\n",
                strerror(errno));
            exit(1);
        }
        payload -= nread;
    }
    close(s); /* Close the file descriptor ASAP as fsync() may take time. */
    fsync(fd);
    fprintf(stderr,"Transfer finished with success.\n");
    exit(0);
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.