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From:   Jithu Joseph <jithu.joseph@intel.com>
To:     ilpo.jarvinen@linux.intel.com, hdegoede@redhat.com,
        markgross@kernel.org
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        rostedt@goodmis.org, jithu.joseph@intel.com, ashok.raj@intel.com,
        tony.luck@intel.com, linux-kernel@vger.kernel.org,
        platform-driver-x86@vger.kernel.org, patches@lists.linux.dev,
        ravi.v.shankar@intel.com, pengfei.xu@intel.com
Subject: [PATCH v4 5/9] platform/x86/intel/ifs: Validate image size
Date:   Thu,  5 Oct 2023 12:51:33 -0700
Message-Id: <20231005195137.3117166-6-jithu.joseph@intel.com>
In-Reply-To: <20231005195137.3117166-1-jithu.joseph@intel.com>
References: <20230929202436.2850388-1-jithu.joseph@intel.com>
 <20231005195137.3117166-1-jithu.joseph@intel.com>
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Perform additional validation prior to loading IFS image.

Error out if the size of the file being loaded doesn't match the size
specified in the header.

Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
---
 drivers/platform/x86/intel/ifs/load.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/platform/x86/intel/ifs/load.c b/drivers/platform/x86/intel/ifs/load.c
index 6b827247945b..582f1801aaaa 100644
--- a/drivers/platform/x86/intel/ifs/load.c
+++ b/drivers/platform/x86/intel/ifs/load.c
@@ -375,6 +375,7 @@ int ifs_load_firmware(struct device *dev)
 {
 	const struct ifs_test_caps *test = ifs_get_test_caps(dev);
 	struct ifs_data *ifsd = ifs_get_data(dev);
+	unsigned int expected_size;
 	const struct firmware *fw;
 	char scan_path[64];
 	int ret = -EINVAL;
@@ -389,6 +390,13 @@ int ifs_load_firmware(struct device *dev)
 		goto done;
 	}
 
+	expected_size = ((struct microcode_header_intel *)fw->data)->totalsize;
+	if (fw->size != expected_size) {
+		dev_err(dev, "File size mismatch (expected %u, actual %zu). Corrupted IFS image.\n",
+			expected_size, fw->size);
+		return -EINVAL;
+	}
+
 	ret = image_sanity_check(dev, (struct microcode_header_intel *)fw->data);
 	if (ret)
 		goto release;
-- 
2.25.1