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Date:   Tue, 15 Mar 2022 16:27:38 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     xkernel.wang@foxmail.com
Cc:     nsaenz@kernel.org, bcm-kernel-feedback-list@broadcom.com,
        linux-rpi-kernel@lists.infradead.org,
        linux-arm-kernel@lists.infradead.org,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] staging: mmal-vchiq: add a check for the return of
 vmalloc()
Message-ID: <YjCwagaijyA2oO8r@kroah.com>
References: <tencent_7F2A8AAFF05125C6FF159033E69B5C108E07@qq.com>
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On Tue, Mar 15, 2022 at 10:42:07PM +0800, xkernel.wang@foxmail.com wrote:
> From: Xiaoke Wang <xkernel.wang@foxmail.com>
> 
> 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@foxmail.com>
> ---
> 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