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Date:   Mon, 25 Sep 2023 18:43:24 +0300 (EEST)
From:   =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>
To:     Jithu Joseph <jithu.joseph@intel.com>
cc:     Hans de Goede <hdegoede@redhat.com>, markgross@kernel.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        rostedt@goodmis.org, ashok.raj@intel.com, tony.luck@intel.com,
        LKML <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: Re: [PATCH v2 5/9] platform/x86/intel/ifs: Validate image size
In-Reply-To: <20230922232606.1928026-6-jithu.joseph@intel.com>
Message-ID: <318e7426-fcab-c1e4-6e84-752c332088f2@linux.intel.com>
References: <20230913183348.1349409-1-jithu.joseph@intel.com> <20230922232606.1928026-1-jithu.joseph@intel.com> <20230922232606.1928026-6-jithu.joseph@intel.com>
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On Fri, 22 Sep 2023, Jithu Joseph wrote:

> 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>
> 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..b09106034fac 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 %d, actual %ld). Corrupted IFS image.\n",
> +			expected_size, fw->size);
> +		return -EBADFD;

I don't think this error code is best suited for what occurred. I guess 
returning just -EINVAL would be fine.

-- 
 i.

> +	}
> +
>  	ret = image_sanity_check(dev, (struct microcode_header_intel *)fw->data);
>  	if (ret)
>  		goto release;
>