Re: [PATCH v3 2/3] remoteproc: qcom_q6v5_mss: Validate modem blob firmware size before load

[Bjorn Andersson <bjorn.andersson@linaro.org>]

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

> The following mem abort is observed when one of the modem blob firmware
> size exceeds the allocated mpss region. Fix this by restricting the copy
> size to segment size using request_firmware_into_buf before load.
> 
> Err Logs:
> Unable to handle kernel paging request at virtual address
> Mem abort info:
> ...
> Call trace:
>   __memcpy+0x110/0x180
>   rproc_start+0xd0/0x190
>   rproc_boot+0x404/0x550
>   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
> ...
> 
> Fixes: 051fb70fd4ea4 ("remoteproc: qcom: Driver for the self-authenticating Hexagon v5")
> Cc: stable@vger.kernel.org
> Signed-off-by: Sibi Sankar <sibis@codeaurora.org>

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

> ---
>  drivers/remoteproc/qcom_q6v5_mss.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
> index 4e72c9e30426c..f4aa61ba220dc 100644
> --- a/drivers/remoteproc/qcom_q6v5_mss.c
> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
> @@ -1174,15 +1174,14 @@ static int q6v5_mpss_load(struct q6v5 *qproc)
>  		} else if (phdr->p_filesz) {
>  			/* Replace "xxx.xxx" with "xxx.bxx" */
>  			sprintf(fw_name + fw_name_len - 3, "b%02d", i);
> -			ret = request_firmware(&seg_fw, fw_name, qproc->dev);
> +			ret = request_firmware_into_buf(&seg_fw, fw_name, qproc->dev,
> +							ptr, phdr->p_filesz);
>  			if (ret) {
>  				dev_err(qproc->dev, "failed to load %s\n", fw_name);
>  				iounmap(ptr);
>  				goto release_firmware;
>  			}
>  
> -			memcpy(ptr, seg_fw->data, seg_fw->size);
> -
>  			release_firmware(seg_fw);
>  		}
>  
> -- 
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> a Linux Foundation Collaborative Project
>