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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: Validate that p_filesz < p_memsz
Date:   Thu,  7 Jan 2021 15:31:19 -0800
Message-Id: <20210107233119.717173-1-bjorn.andersson@linaro.org>
MIME-Version: 1.0
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The code validates that segments of p_memsz bytes of a segment will fit
in the provided memory region, but does not validate that p_filesz bytes
will, which means that an incorrectly crafted ELF header might write
beyond the provided memory region.

Fixes: 051fb70fd4ea ("remoteproc: qcom: Driver for the self-authenticating Hexagon v5")
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 e01d18e9ad2b..5180b5996830 100644
--- a/drivers/soc/qcom/mdt_loader.c
+++ b/drivers/soc/qcom/mdt_loader.c
@@ -230,6 +230,14 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
 			break;
 		}
 
+		if (phdr->p_filesz > phdr->p_memsz) {
+			dev_err(dev,
+				"refusing to load segment %d with p_filesz > p_memsz\n",
+				i);
+			ret = -EINVAL;
+			break;
+		}
+
 		ptr = mem_region + offset;
 
 		if (phdr->p_filesz && phdr->p_offset < fw->size) {
-- 
2.29.2