linux-kernel - Re: [PATCH v2 08/21] coco/tdx-host: Implement FW

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aS6TSlT24kB80rL4@intel.com>
Date: Tue, 2 Dec 2025 15:20:42 +0800
From: Chao Gao <chao.gao@...el.com>
To: Binbin Wu <binbin.wu@...ux.intel.com>
CC: <linux-coco@...ts.linux.dev>, <linux-kernel@...r.kernel.org>,
	<x86@...nel.org>, <reinette.chatre@...el.com>, <ira.weiny@...el.com>,
	<kai.huang@...el.com>, <dan.j.williams@...el.com>,
	<yilun.xu@...ux.intel.com>, <sagis@...gle.com>, <vannapurve@...gle.com>,
	<paulmck@...nel.org>, <nik.borisov@...e.com>, Farrah Chen
	<farrah.chen@...el.com>, Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar
	<mingo@...hat.com>, Borislav Petkov <bp@...en8.de>, Dave Hansen
	<dave.hansen@...ux.intel.com>, "H. Peter Anvin" <hpa@...or.com>, "Kirill A.
 Shutemov" <kas@...nel.org>
Subject: Re: [PATCH v2 08/21] coco/tdx-host: Implement FW_UPLOAD sysfs ABI
 for TDX Module updates

On Mon, Nov 24, 2025 at 03:49:34PM +0800, Binbin Wu wrote:
>
>
>On 10/1/2025 10:52 AM, Chao Gao wrote:
>[...]
>> +static enum fw_upload_err tdx_fw_prepare(struct fw_upload *fwl,
>> +					 const u8 *data, u32 size)
>> +{
>> +	struct tdx_fw_upload_status *status = fwl->dd_handle;
>> +
>> +	if (status->cancel_request) {
>> +		status->cancel_request = false;
>> +		return FW_UPLOAD_ERR_CANCELED;
>> +	}
>> +
>> +	return FW_UPLOAD_ERR_NONE;
>> +}
>> +
>> +static enum fw_upload_err tdx_fw_write(struct fw_upload *fwl, const u8 *data,
>> +				       u32 offset, u32 size, u32 *written)
>> +{
>> +	struct tdx_fw_upload_status *status = fwl->dd_handle;
>> +
>> +	if (status->cancel_request) {
>> +		status->cancel_request = false;
>> +		return FW_UPLOAD_ERR_CANCELED;
>> +	}
>
>Since the execution of the work is not protected by the mutex, if userspace
>requests cancellation after this point, after the TDX module update finished,
>it seems that the cancel value is left over and it could impact the next update?

Yes, I think this is a bug. A few other drivers just clear "cancel_request" in
the "prepare" phase, e.g., pd692x0_fw_prepare(), mpfs_auto_update_prepare(),
m10bmc_sec_prepare(). I will follow that approach.