[PATCH 4.19 203/425] soc: qcom: mdt_loader: Detect truncated read of segments

[Greg Kroah-Hartman]

From: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>

[ Upstream commit 0648c55e3a21ccd816e99b6600d6199fbf39d23a ]

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()")
Reviewed-by: Sibi Sankar <sibis@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210107232526.716989-1-bjorn.andersson@xxxxxxxxxx
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/soc/qcom/mdt_loader.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c
index 7584b81d06a1..47dffe7736ff 100644
--- a/drivers/soc/qcom/mdt_loader.c
+++ b/drivers/soc/qcom/mdt_loader.c
@@ -187,6 +187,15 @@ 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);
+				release_firmware(seg_fw);
+				ret = -EINVAL;
+				break;
+			}
+
 			release_firmware(seg_fw);
 		}
 
-- 
2.30.2