Realloc failing after second call - c

Question

I'm attempting to read in a list of words to be sorted and I start out with a fairly small array (10 elements) and then would like to increase the size of the array by 10 if the current capacity isn't enough. This seems to work with the first realloc, but I get a SIGABRT when trying to call realloc again. I'm sure it is a simple thing I'm not seeing, but I can't seem to figure it out. Here is my program:
int main(int argc, char *argv[]){
char *string = malloc(100);
// Array of pointers starting with 100 elements
char **toSort = malloc(100*sizeof(char *));
if(toSort == NULL) {
exit(1);
}
for(int i = 0; i < 100; i++) {
// Each string can be up to 100 characters long
toSort[i] = malloc(101);
if(toSort[i] == NULL) {
exit(1);
}
}
// Get all lines in the file
int counter = 0;
int max = 10;
char *toAdd;
FILE *txt = fopen("wlist0.txt", "r");
while(fgets ( string, 100, txt ) && counter < max) {;
toAdd = malloc(100);
if(toAdd == NULL) {
exit(1);
}
strcpy(toAdd, string);
toSort[counter] = string;
counter++;
//if the array needs to be enlarged
if(counter == max) {
char **new = realloc(toSort, (max+10) * sizeof(char));
if(new == NULL) {
exit(1);
}
for(int i = max; i < max + 10; i++) {
toSort[i] = malloc(101);
if(toSort[i] == NULL) {
exit(1);
}
}
toSort = new;
max += 10;
}
};
for(int i = 0; i < max; i++) {
char *word = toSort[i];
printf("%s", word);
}
for(int i = 0; i < max; i++) {
free(toSort[i]);
}
free(toSort);
return 0;
};
Like my comments say, my strings have a maximum length of 100 characters. I suppose I could dynamically allocate memory for the strings as well, but I'll worry about that when I have the other realloc working. Any help would be greatly appreciated.

Answer 1

This code assigns values to toSort after it the memory it points to is freed/modified by realloc():
//if the array needs to be enlarged
if(counter == max) {
char **new = realloc(toSort, (max+10) * sizeof(char));
if(new == NULL) {
exit(1);
}
for(int i = max; i < max + 10; i++) {
toSort[i] = malloc(101); <--- toSort is invalid here
if(toSort[i] == NULL) {
exit(1);
}
}
toSort = new;
max += 10;
}
This will work better:
//if the array needs to be enlarged
if(counter == max) {
char **new = realloc(toSort, (max+10) * sizeof( *new )); <-- fixed here, too
if(new == NULL) {
exit(1);
}
toSort = new;
for(int i = max; i < max + 10; i++) {
toSort[i] = malloc(101);
if(toSort[i] == NULL) {
exit(1);
}
}
max += 10;
}
There may be other errors in your code. I haven't fully examined it.