Hard Fault when dynamic memory allocaion in stm32f7

I am trying to implement a system so that it retrieves sound and extracts the mfcc of it. I'd like to implement my own mfcc function because librosa library wasn't implemented in C and other implementations of mfcc extractions doesn't yield the same outputs as librosa library does. So I wrote a code, however, when I would like create hanning window, program doesn't take a step further and always stays the same statement while debugging. The statement is below:

float *mul = malloc(sizeof(float)*fftsize);

The whole code is as follows:

float* hanning(int fftsize){

     float *mul = malloc(sizeof(float)*fftsize);

     for (int i = 0; i<fftsize; i++){

         mul[i] = 0.5 * (1 - cos(2*PI*i/(fftsize-1)));

     }

     return mul;
}

I put an LCD code to all error handler functions in stm32f7xx_it.c file to determine which fault I'm facing, and I see that it is hard_fault.

So what's the problem? I hope the issue is explained clearly. Due to the privacy, I couldn't put here whole code. Sorry for that. Thx in advance for your response.

Edit: I am chaning malloc to normal array with a variable length array. But still it takes me to HardFault_Handler function. SCB->SHCSR returns sometimes 65535 and sometimes 1.