HardFault_Handler with arm_lms_ functions

Hi everyone,

I'm currently developping an app with STM32F4 - discovery board.
I'm sampling some sounds with the microphone and the DMA, and i analize it with signal processing.

I'm using the CMSIS arm_lms_f32 function

void arm_lms_f32        (       const arm_lms_instance_f32 *    S,
                float32_t *     pSrc,
                float32_t *     pRef,
                float32_t *     pOut,
                float32_t *     pErr,
                uint32_t        blockSize
        )

All my buffers PSrc,PRef... are initialized with
float32_t PSrc[blockSize ];

The instance structure is initialized with

arm_lms_init_f32(&S, NUM_TAPS, firCoeffs32,
                         firStateF32, beta, blockSize );

The code works fine and realize the sound processing i want.
But when i increase the "blockSize" the programm counter jump in hard_fault after calling arm_lms_f32.

I tried to look at the arm_lms_f32 code :
github.com/.../arm_lms_f32.c

Tried to look at my memory and increase my stack value.
But nothing changes, for a blocksize > 8 a hardfault interrupt is generated.

Does someone know why ?
Thanks a lot for your help.