Q: Given the following code slice:
```
1 static int  readSeparateTilesIntoBuffer (TIFF* in, uint8 *obuf, 
2 					 uint32 imagelength, uint32 imagewidth, 
3                                          uint32 tw, uint32 tl,
4                                          uint16 spp, uint16 bps)
9   uint32  row, col;     /* Current row and col of image */
10   uint32  nrow, ncol;   /* Number of rows and cols in current tile */
11   uint32  row_offset, col_offset; /* Output buffer offsets */
12   tsize_t tbytes = 0, tilesize = TIFFTileSize(in);
13   tsample_t s;
15   unsigned char *srcbuffs[MAX_SAMPLES];
20   for (sample = 0; (sample < spp) && (sample < MAX_SAMPLES); sample++)
22     srcbuffs[sample] = NULL;
23     tbuff = (unsigned char *)_TIFFmalloc(tilesize + 8);
24     if (!tbuff)
32     srcbuffs[sample] = tbuff;
37   for (row = 0; row < imagelength; row += tl)
39     nrow = (row + tl > imagelength) ? imagelength - row : tl;
40     for (col = 0; col < imagewidth; col += tw)
42       for (s = 0; s < spp; s++)
44 	tbytes = TIFFReadTile(in, srcbuffs[s], col, row, 0, s);
45         if (tbytes < 0  && !ignore)
66       if (col + tw > imagewidth)
67         ncol = imagewidth - col;
69         ncol = tw;
71       row_offset = row * (((imagewidth * spp * bps) + 7) / 8);
72       col_offset = ((col * spp * bps) + 7) / 8;
73       bufp = obuf + row_offset + col_offset;
75       if ((bps % 8) == 0)
77         if (combineSeparateTileSamplesBytes(srcbuffs, bufp, ncol, nrow, imagewidth,```
which has a CWE-125 vulnerability at line:
```
42       for (s = 0; s < spp; s++)
```
Please analyze the root cause of the vulnerability.