fgets() 에서 블럭되어요..

스택모양입니다.

----- Thread 916 ----- 
0x15685f44: __read + 0x14 (0, 1556e000, 1000, 156dbdf4, 3ffecd48, 156dbdf4) 
0x15621a26: _IO_file_read + 0x26 (8070af8, 1556e000, 1000, 15620b0e, 156d2b9c, 3ffed0b0) + 20 
0x15620c2d: _IO_new_file_underflow + 0x12d (8070af8, 0, 0, 1555f4a1, 0, 8070af8) 
0x156234c9: _IO_default_uflow + 0x19 (8070af8, 332e312e, 155d0033, 1562240a, 156dbdf4, 1556e5b6) 
0x156224ff: __uflow + 0xff (8070af8, 0, 0, 15617c72, 0, 0) + 20 
0x15617d6d: _IO_getline_info + 0x109 (8070af8, 3ffed110, ff, a, 1, 0) + 10 
0x15617e4d: _IO_getline + 0x2d (8070af8, 3ffed110, ff, a, 1, 1559a010) + 40 
0x15616c94: fgets + 0x90 (3ffed110, 100, 8070af8, 3ffed260, 0, 0) + 110 
0x0805a06b: get_next_line + 0x2f (3ffed260, 8070af8, 3ffed258, 8070058, 1556cc00, 8048d48) + 130 

char *get_next_line(char *line, FILE *conf_file)
{
        char    *ret    = NULL;
        char    buf[MAX_LINE_LEN];

        do {
                ret = NULL;
                memset(buf, 0, MAX_LINE_LEN);
                if (!(ret = fgets(buf, MAX_LINE_LEN, conf_file))) 
                          break;
                while (isspace(*ret)) ret++;
                strcpy(line, ret);
        } while (*ret == '\0' || *ret == '#');

        return ret;
}

커널 2.4.9-e.34
gcc version 2.96 에서 컴파일했습니다.
fgets() 에서 멈춰버려요.
파라미터는 정상적인것 같은데, 시스템 호출에서 멈추니 당황스럽네요.