Re: [PATCH v3] staging: media: atomisp: fix memory leak of dvs2_coeff

[Dan Carpenter <error27@gmail.com>]

On Fri, Apr 17, 2026 at 03:01:24PM +0800, Huihui Huang wrote:
> There is a memory leak in
> drivers/staging/media/atomisp/pci/atomisp_compat_css20.c.
> 
> In atomisp_alloc_dis_coef_buf(), dvs2_coeff is allocated by
> ia_css_dvs2_coefficients_allocate() and stored in
> asd->params.css_param.dvs2_coeff. If the subsequent
> ia_css_dvs2_statistics_allocate() for dvs_stat fails, the function
> returns -ENOMEM without freeing the previously allocated dvs2_coeff.
> 
> Add the missing ia_css_dvs2_coefficients_free() call before returning
> on the error path.
> 
> Signed-off-by: Huihui Huang <hhhuang@smu.edu.sg>
> ---
> v3: Remove unnecessary NULL assignment per review feedback.
> v2: Reword commit message per review feedback (no code change).
> ---
>  drivers/staging/media/atomisp/pci/atomisp_compat_css20.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> index be5f37f4a6fd..d6e135c42e2f 100644
> --- a/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> +++ b/drivers/staging/media/atomisp/pci/atomisp_compat_css20.c
> @@ -1363,8 +1363,10 @@ int atomisp_alloc_dis_coef_buf(struct atomisp_sub_device *asd)
>  	/* DIS projections. */
>  	asd->params.dis_proj_data_valid = false;
>  	asd->params.dvs_stat = ia_css_dvs2_statistics_allocate(dvs_grid);
> -	if (!asd->params.dvs_stat)
> +	if (!asd->params.dvs_stat) {
> +		ia_css_dvs2_coefficients_free(asd->params.css_param.dvs2_coeff);
>  		return -ENOMEM;
> +	}

The design of this code is that if we have an -ENOMEM here the caller,
atomisp_update_grid_info(), calls atomisp_css_free_stat_buffers() which
calls ia_css_dvs2_coefficients_free().  I can't tell if adding a second
ia_css_dvs2_coefficients_free() here leads to a double free.

I call this style of error handling One Magical Cleanup Function.  It's
always buggy...
https://staticthinking.wordpress.com/2025/03/31/reviewing-magical-cleanup-functions/

regards,
dan carpenter