Valgrind错误，读取的大小为1-C

Question

我的程序在一定数量的递归下一直崩溃，而调试时我偶然发现了一些valgrind错误。

我一直在尝试解决这些问题？但是我一定会误解该错误，如果有人能够对这些错误进行扩展的解释，将不胜感激。

多个：

==5367== Invalid read of size 1
==5367==    at 0x100000F60: ft_validator (validator.c:29)
==5367==    by 0x100001139: ft_sort_list (sort_list.c:35)
==5367==    by 0x100000DD5: main (main.c:41)

我的ft_validator：

/*
** Checks if the tetrimino's are valid and
** if each Tetrimino Block touches atleast another block.
** Check if the read '#' tetrimino block has any adjacent blocks,
** if not, we can discard the tetrimino.
** @return 0 = Valid tetrimino set, -1 is invalid tetrimino set
** @param buf represents the string containing the tetrimino sample set.
*/

int         ft_validator(char *buf, int blocks, int adjacent, int dots)
{
    int index;

    index = 0;
    while (buf[index] != '\0')
    {
        if ((buf[index] != '#' && buf[index] != '.' && buf[index] != '\n'))
            return (-1);
        if (buf[index] == '#')
        {
            blocks++;
            if (buf[index - 1] == '#')
                adjacent++;
            if (buf[index + 1] == '#')
                adjacent++;
            if (buf[index + 5] == '#')
                adjacent++;
            if (buf[index - 5] == '#')
                adjacent++;
        }
        buf[index] != '.' || dots++;
        index++;
    }
    if (adjacent < 6 || blocks != 4 || dots != 12)
        return (-1);
    return (0);
}

这：

==5367==  Address 0x100b58ca5 is 0 bytes after a block of size 21 alloc'd
==5367==    at 0x1000991E6: malloc (in /Users/dvan-boc/.brew/Cellar/valgrind/3.14.0/lib/valgrind/vgpreload_memcheck-amd64-darwin.so)
==5367==    by 0x100000E54: ft_read (reader.c:38)
==5367==    by 0x100000DC3: main (main.c:40)
==5367== 

/*
**
** @param file represents the file name to be read.
** @return returns an integer
** Reads a file containing multiple tetrmino's ranging from 1 to 26 tetrimino's
** Every # is recognized as a Tetrimino_Block and every . is ignored
** @PURPOSE:
** The purpose of the tetrimino's is to find the smallest
** possible solution to the smallest possible square
**
** EXAMPLE:
** Coords start at 0, 0 and end at 4, 4
*/

int     ft_read(const char *file, char **buf)
{
    int fd;
    int t_index;
    int ret;

    t_index = 0;
    fd = open(file, O_RDONLY);
    buf[t_index] = malloc(BUFF_SIZE * sizeof(**buf));
    ret = read(fd, buf[t_index], BUFF_SIZE);
    t_index++;
    while (ret == 21 && t_index < 27)
    {
        buf[t_index] = malloc(BUFF_SIZE * sizeof(**buf));
        ret = read(fd, buf[t_index], BUFF_SIZE);
        t_index++;
    }
    if (ret != 20 || t_index == 27)
        return (-t_index);
    buf[t_index] = NULL;
    return (t_index);
}