Q: Given the following code slice:
```
1 static int
2 process_cu_tu_index (struct dwarf_section *section, int do_display)
4   unsigned char *phdr = section->start;
5   unsigned char *limit = phdr + section->size;
6   unsigned char *phash;
7   unsigned char *pindex;
8   unsigned char *ppool;
9   unsigned int version;
10   unsigned int ncols = 0;
11   unsigned int nused;
12   unsigned int nslots;
13   unsigned int i;
20   if (phdr == NULL)
26   if (section->size < 24)
39   phash = phdr + 16;
40   pindex = phash + nslots * 8;
41   ppool = pindex + nslots * 4;
44   if (pindex < phash || ppool < phdr || (pindex == phash && nslots != 0))
64   if (ppool > limit || ppool < phdr)
71   if (version == 1)
122   else if (version == 2)
126       unsigned char *ph = phash;
128       unsigned char *poffsets = ppool + ncols * 4;
129       unsigned char *psizes = poffsets + nused * ncols * 4;
130       unsigned char *pend = psizes + nused * ncols * 4;
131       bfd_boolean is_tu_index;
132       struct cu_tu_set *this_set = NULL;
133       unsigned int row;
134       unsigned char *prow;
136       is_tu_index = strcmp (section->name, ".debug_tu_index") == 0;
140       if (poffsets < ppool || (unsigned int) ((poffsets - ppool) / 4) != ncols)
146       if (pend > limit)
153       if (do_display)
161 	  if (is_tu_index)
164 	      tu_sets = xcalloc2 (nused, sizeof (struct cu_tu_set));
165 	      this_set = tu_sets;
170 	      cu_sets = xcalloc2 (nused, sizeof (struct cu_tu_set));
171 	      this_set = cu_sets;
185       for (i = 0; i < nslots; i++)
190 	  if (row != 0)
193 	      if (row > nused)
200 	      if (!do_display)
201 		memcpy (&this_set[row - 1].signature, ph, sizeof (uint64_t));
203 	      prow = poffsets + (row - 1) * ncols * 4;
205 	      if (prow < poffsets || prow > limit)
236 	  ph += 8;```
which has a CWE-125 vulnerability at line:
```
201 		memcpy (&this_set[row - 1].signature, ph, sizeof (uint64_t));
```
Please analyze the root cause of the vulnerability.