linux-kernel - Re: [PATCH 2/3] efi: stmm: Use EFI return code of setup_mm

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: <3a9eb8eb-3420-4232-8259-3b33ed45dc66@siemens.com>
Date: Thu, 21 Aug 2025 15:00:13 +0200
From: Jan Kiszka <jan.kiszka@...mens.com>
To: Ilias Apalodimas <ilias.apalodimas@...aro.org>
Cc: Ard Biesheuvel <ardb@...nel.org>,
 Masahisa Kojima <masahisa.kojima@...aro.org>, linux-efi@...r.kernel.org,
 linux-kernel@...r.kernel.org, Sumit Garg <sumit.garg@...aro.org>,
 Jens Wiklander <jens.wiklander@...aro.org>
Subject: Re: [PATCH 2/3] efi: stmm: Use EFI return code of setup_mm_hdr

On 20.08.25 16:59, Jan Kiszka wrote:
> On 20.08.25 09:10, Ilias Apalodimas wrote:
>> Hi Jan
>>
>> On Fri, 15 Aug 2025 at 22:12, Jan Kiszka <jan.kiszka@...mens.com> wrote:
>>>
>>> From: Jan Kiszka <jan.kiszka@...mens.com>
>>>
>>> If a too large payload_size is passed to setup_mm_hdr, callers will
>>> returned EFI_OUT_OF_RESOURCES rather than EFI_INVALID_PARAMETER that is
>>> passed down via ret. No need to fold errors here.
>>
>> Apart from not folding the error here, the current code kind of
>> violates the EFI spec.
>> If you look at GetVariable, GetNextVariable, SetVariable, and
>> QueryVariableInfo only SetVariable is supposed to return
>> EFI_OUT_OF_RESOURCES, if there's no storage space left.
> 
> And with storage space is likely meant the persistent part of it. ENOMEM
> is something different.
> 
>>
>> Should we also change setup_mm_hdr() and return EFI_INVALID_PARAMETER
>> always? It's still not ideal, but much closer to the spec.
> 
> EFI_DEVICE_ERROR? The "hardware" is has a problem by not providing us
> enough RAM. Yeah, not optimal either. But invalid parameter is clearly
> described, and nothing fits.
> 

If there are no concerns, I will switch to EFI_DEVICE_ERROR and even
drop the error "ret" argument in v2.

Jan

-- 
Siemens AG, Foundational Technologies
Linux Expert Center