为什么地址清理程序会在我的乘法矩阵中导致堆缓冲区溢出错误？

Question

The error is: heap-buffer-overflow . I'm running a block of code that multiplies matrices. Address sanitizer is throwing me an error at a specific line while trying to multiply two matrices. On my IDE, no errors or warnings show up, however, address sanitizer is throwing an error here and I'm not too sure why. The matrix has entries scanned in from the user, below is a snippet of the code not working. The snippet address sanitizer is throwing an error on is bolded. Thanks.

snippet:

double **productMatrixT;

productMatrixT = (double **)malloc(rowT*sizeof(double));
for(i = 0; i < rowT; i++)
{
  productMatrixT[i] = malloc(column*sizeof(double));
}

double sum = 0;
for(i = 0; i < column; i++)
{
  for(j = 0; j < row; j++)
   {
     for(k = 0; k < rowT; k++)
      {
        **sum = sum + matrixT[i][k] * matrix[k][j];** <---- /*says this line is a cause for a problem*/
      }
       productMatrixT[i][j] = sum;
       sum = 0;
     }
  }
}

free:

for(i = 0; i < rowT; i++)
{
 free(productMatrixT[i]);
}
free(productMatrixT);

Answer 1

regarding:

double sum = 0;

since it is declared as a double , it should be initialized as a double , IE

double sum = 0.0;

regarding:

**sum = sum + matrixT[i][k] * matrix[k][j];

since 'sum' is a double and not a pointer to a pointer, the ** dereferencing is resulting in some random address. This is what the address sanitizer is complaining about.

As others have mentioned, there is plenty more wrong with the posted code.

Answer 2

Your indexing is wrong, in

sum = sum + matrixT[i][k] * matrix[k][j];

you access matrix as column x rowT and rowT x row but you've allocated it as rowT x column .

Also you should fix

productMatrixT = (double **)malloc(rowT*sizeof(double));

to be

productMatrixT = (double **)malloc(rowT*sizeof(double *));