Address sanitizer SEGV unknown error caused by reading a file

Question

so I am trying to input text from a file to make a square matrix multiplication algorithm. My first function actually fills all the m[I][J] entries from the file. The text file is formatted like this:

3 //an int that determines the size of the square matrix so in this case 3X3
1 2 3 //the entries for the matrix, N lines of numbers with N numbers in each line
4 5 6 
7 8 9
2 // the exponent to multiply the matrix

So the SEGV error is caused by line 15 which is fscanf(file, "%d", &m1[i][j]);

here is the entire method in question

void matrixFill(int** m1, int** m2,int n){

int i,j;

     for(i=0; i<n;i++){
       for(j=0;j<n;j++){

          fscanf(file, "%d", &m1[i][j]);

          m2[i][j] = m1[i][j];
       }
    }
}
int main (int argc, char** argv){

    file = fopen(argv[1], "r");

    int size;

    fscanf(file, "%d", &size);

    int **matrixOne = (int **)malloc(size * sizeof(int *));
    int **matrixTwo = (int **)malloc(size * sizeof(int *));
    int **result = (int **)malloc(size * sizeof(int *));

    matrixFill(matrixOne,matrixTwo,size);
    
    return 0;

}

Am I even scanning the file right? Keep in mind the first number (the dimension) is already scanned so I think it will start scanning from the 1.

[Edit] the question to include a [mre]. The caller of `matrixFill` is likely not properly creating the `m1` matrix. — 1201ProgramAlarm, Oct 16 '21 at 00:36
does the `file` variable exists in `matrixFill` scope? if it's not you need another `fopen` before your `fscan`. — iѕєρєня, Oct 16 '21 at 00:53
You're not properly allocating the array, as the `matrixOne` array is a bunch of uninitialized pointers. See [here](https://stackoverflow.com/questions/2128728/allocate-matrix-in-c). — 1201ProgramAlarm, Oct 16 '21 at 00:58
Even better: [**Correctly allocating multi-dimensional arrays**](https://stackoverflow.com/questions/42094465/correctly-allocating-multi-dimensional-arrays) — Andrew Henle, Oct 16 '21 at 01:26

Address sanitizer SEGV unknown error caused by reading a file

0 Answers0