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

From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Siddharth Gupta <sidgup@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] soc: qcom: mdt_loader: Detect truncated read of segments
Date: Thu,  7 Jan 2021 15:25:26 -0800	[thread overview]
Message-ID: <20210107232526.716989-1-bjorn.andersson@linaro.org> (raw)

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

