Re: [PATCH v3 1/3] remoteproc: qcom_q6v5_mss: Validate MBA firmware size before load

From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Sibi Sankar <sibis@codeaurora.org>
Cc: agross@kernel.org, linux-arm-msm@vger.kernel.org,
	linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org,
	evgreen@chromium.org, ohad@wizery.com, stable@vger.kernel.org
Subject: Re: [PATCH v3 1/3] remoteproc: qcom_q6v5_mss: Validate MBA firmware size before load
Date: Mon, 27 Jul 2020 22:45:03 -0700	[thread overview]
Message-ID: <20200728054503.GA349841@builder.lan> (raw)
In-Reply-To: <20200722201047.12975-2-sibis@codeaurora.org>

On Wed 22 Jul 13:10 PDT 2020, Sibi Sankar wrote:

> The following mem abort is observed when the mba firmware size exceeds
> the allocated mba region. MBA firmware size is restricted to a maximum
> size of 1M and remaining memory region is used by modem debug policy
> firmware when available. Hence verify whether the MBA firmware size lies
> within the allocated memory region and is not greater than 1M before
> loading.
> 
> Err Logs:
> Unable to handle kernel paging request at virtual address
> Mem abort info:
> ...
> Call trace:
>   __memcpy+0x110/0x180
>   rproc_start+0x40/0x218
>   rproc_boot+0x5b4/0x608
>   state_store+0x54/0xf8
>   dev_attr_store+0x44/0x60
>   sysfs_kf_write+0x58/0x80
>   kernfs_fop_write+0x140/0x230
>   vfs_write+0xc4/0x208
>   ksys_write+0x74/0xf8
>   __arm64_sys_write+0x24/0x30
> ...
> 
> Fixes: 051fb70fd4ea4 ("remoteproc: qcom: Driver for the self-authenticating Hexagon v5")
> Cc: stable@vger.kernel.org

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>

> Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
> ---
>  drivers/remoteproc/qcom_q6v5_mss.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
> index 718acebae777f..4e72c9e30426c 100644
> --- a/drivers/remoteproc/qcom_q6v5_mss.c
> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
> @@ -412,6 +412,12 @@ static int q6v5_load(struct rproc *rproc, const struct firmware *fw)
>  {
>  	struct q6v5 *qproc = rproc->priv;
>  
> +	/* MBA is restricted to a maximum size of 1M */
> +	if (fw->size > qproc->mba_size || fw->size > SZ_1M) {
> +		dev_err(qproc->dev, "MBA firmware load failed\n");

I'll change this to "MBA firmware exceeds size limit\n". Please let me
know if you object.

Regards,
Bjorn

> +		return -EINVAL;
> +	}
> +
>  	memcpy(qproc->mba_region, fw->data, fw->size);
>  
>  	return 0;
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 