linux-kernel - Re: [PATCH v4 0/2] generate boot_aggregate log in IMA with TPM using CRB over FF-A

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: <aFs0of3uZdoMEJXc@kernel.org>
Date: Wed, 25 Jun 2025 02:28:33 +0300
From: Jarkko Sakkinen <jarkko@...nel.org>
To: Yeoreum Yun <yeoreum.yun@....com>
Cc: sudeep.holla@....com, peterhuewe@....de, jgg@...pe.ca,
	stuart.yoder@....com, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org, linux-integrity@...r.kernel.org
Subject: Re: [PATCH v4 0/2] generate boot_aggregate log in IMA with TPM using
 CRB over FF-A

On Wed, Jun 18, 2025 at 11:23:00AM +0100, Yeoreum Yun wrote:
> To ensure the TPM device operating over the FF-A protocol with
> the CRB interface is probed before IMA initialization,
> the following conditions must be met:
> 
>    1. The corresponding ffa_device must be registered,
>       which is done via ffa_init().
> 
>    2. The tpm_crb_driver must successfully probe this device via
>       tpm_crb_ffa_init().
> 
>    3. The tpm_crb driver using CRB over FF-A can then
>       be probed successfully. (See crb_acpi_add() and
>       tpm_crb_ffa_init() for reference.)
> 
> Unfortunately, ffa_init(), tpm_crb_ffa_init(), and crb_acpi_driver_init() are
> all registered with device_initcall, which means crb_acpi_driver_init() may
> be invoked before ffa_init() and tpm_crb_ffa_init() are completed.

I get the ffa_init() part i.e, moving it earlier. However for
tpm_crb_ffa_init() and crb_acpi_driver_init(), modules.dep
takes care that they are loaded in order.

For IMA you will need the driver as built-in but that should
be handled via kernel config, not via code changes.

BR, Jarkko