Re: [PATCH v2] staging: mmal-vchiq: add a check for the return of vmalloc()

[Greg KH]

On Tue, Mar 15, 2022 at 10:42:07PM +0800, xkernel.wang@xxxxxxxxxxx wrote:
> From: Xiaoke Wang <xkernel.wang@xxxxxxxxxxx>
> 
> vmalloc() is a memory allocation API which can return NULL when some
> internal memory errors happen. So it is better to check the return
> value of it to catch the error in time.
> 
> Signed-off-by: Xiaoke Wang <xkernel.wang@xxxxxxxxxxx>
> ---
> ChangeLog:
> v1->v2  jump to the proper location and remove redundant instruction.
>  drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> index 76d3f03..ff4b484 100644
> --- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> +++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> @@ -1909,6 +1909,10 @@ int vchiq_mmal_init(struct vchiq_mmal_instance **out_instance)
>  	mutex_init(&instance->vchiq_mutex);
>  
>  	instance->bulk_scratch = vmalloc(PAGE_SIZE);
> +	if (!instance->bulk_scratch) {
> +		err = -ENOMEM;
> +		goto err_free;
> +	}
>  	instance->vchiq_instance = vchiq_instance;
>  
>  	mutex_init(&instance->context_map_lock);
> -- 

Your change just crashed the kernel :(

Please be more careful.

greg k-h