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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Ofir Bitton <obitton@habana.ai>,
        Oded Gabbay <oded.gabbay@gmail.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.8 19/42] habanalabs: validate FW file size
Date:   Mon, 31 Aug 2020 11:29:11 -0400
Message-Id: <20200831152934.1023912-19-sashal@kernel.org>
In-Reply-To: <20200831152934.1023912-1-sashal@kernel.org>
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From: Ofir Bitton <obitton@habana.ai>

[ Upstream commit bce382a8bb080ed5f2f3a06754526dc58b91cca2 ]

We must validate FW size in order not to corrupt memory in case
a malicious FW file will be present in system.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/misc/habanalabs/firmware_if.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/misc/habanalabs/firmware_if.c b/drivers/misc/habanalabs/firmware_if.c
index d27841cb5bcb3..345c228a7971e 100644
--- a/drivers/misc/habanalabs/firmware_if.c
+++ b/drivers/misc/habanalabs/firmware_if.c
@@ -13,6 +13,7 @@
 #include <linux/io-64-nonatomic-lo-hi.h>
 #include <linux/slab.h>
 
+#define FW_FILE_MAX_SIZE	0x1400000 /* maximum size of 20MB */
 /**
  * hl_fw_load_fw_to_device() - Load F/W code to device's memory.
  * @hdev: pointer to hl_device structure.
@@ -45,6 +46,14 @@ int hl_fw_load_fw_to_device(struct hl_device *hdev, const char *fw_name,
 
 	dev_dbg(hdev->dev, "%s firmware size == %zu\n", fw_name, fw_size);
 
+	if (fw_size > FW_FILE_MAX_SIZE) {
+		dev_err(hdev->dev,
+			"FW file size %zu exceeds maximum of %u bytes\n",
+			fw_size, FW_FILE_MAX_SIZE);
+		rc = -EINVAL;
+		goto out;
+	}
+
 	fw_data = (const u64 *) fw->data;
 
 	memcpy_toio(dst, fw_data, fw_size);
-- 
2.25.1