[PATCH] soc: qcom: mdt_loader: Detect truncated read of segments

[PATCH] soc: qcom: mdt_loader: Detect truncated read of segments

[Bjorn Andersson]

Given that no validation of how much data the firmware loader read in
for a given segment truncated segment files would best case result in a
hash verification failure, without any indication of what went wrong.

Improve this by validating that the firmware loader did return the
amount of data requested.

Fixes: 445c2410a449 ("soc: qcom: mdt_loader: Use request_firmware_into_buf()")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
 drivers/soc/qcom/mdt_loader.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
index 24cd193dec55..e01d18e9ad2b 100644
--- a/drivers/soc/qcom/mdt_loader.c
+++ b/drivers/soc/qcom/mdt_loader.c
@@ -253,6 +253,14 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
 				break;
 			}
 
+			if (seg_fw->size != phdr->p_filesz) {
+				dev_err(dev,
+					"failed to load segment %d from truncated file %s\n",
+					i, fw_name);
+				ret = -EINVAL;
+				break;
+			}
+
 			release_firmware(seg_fw);
 		}
 
-- 
2.29.2

Re: [PATCH] soc: qcom: mdt_loader: Detect truncated read of segments

[Sibi Sankar]

Hey Bjorn,

Thanks for the patch!

On 1/8/21 4:55 AM, Bjorn Andersson wrote:
> Given that no validation of how much data the firmware loader read in
> for a given segment truncated segment files would best case result in a
> hash verification failure, without any indication of what went wrong.
> 
> Improve this by validating that the firmware loader did return the
> amount of data requested.
> 
> Fixes: 445c2410a449 ("soc: qcom: mdt_loader: Use request_firmware_into_buf()")
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>   drivers/soc/qcom/mdt_loader.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
> index 24cd193dec55..e01d18e9ad2b 100644
> --- a/drivers/soc/qcom/mdt_loader.c
> +++ b/drivers/soc/qcom/mdt_loader.c
> @@ -253,6 +253,14 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
>   				break;
>   			}
>   
> +			if (seg_fw->size != phdr->p_filesz) {
> +				dev_err(dev,
> +					"failed to load segment %d from truncated file %s\n",
> +					i, fw_name);
> +				ret = -EINVAL;
> +				break;

seg_fw has to be released on error condition as well.
With ^^ fixed you can have my R-b.

Reviewed-by: Sibi Sankar <sibis@codeaurora.org>

> +			}
> +
>   			release_firmware(seg_fw);
>   		}
>   
> 

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