From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A672B2DA76F; Wed, 22 Apr 2026 18:46:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776883571; cv=none; b=GKHLu7bpdrcraN5fomC7EN8C3fJ6OY1uObaG2nmWjgw3uWNIj/ElZ+/xNbfEd4yGPHekr05ynW3mm0SdxflzZ3q6EJQ31bPbB6VEMPsl8Y3hWZQVc3Lrp4VjSfRU0fKn+Q7pVLK2dsFq29vIiy81qsVaMsv/epV/VNmfWvOQPNw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776883571; c=relaxed/simple; bh=YL9Q/CEimzmzvwqCzwcq+9U08GB6hZYu6L+QSbxPgrw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MsePRc+ALM1PJuswQmQhkCf6hbP20MtLKy8NLJCS8kuVgyBuoQQkPqeatAHBiN2SG1pGJMOxv/jNnQ2i0nwzk9YpAgpnwlhZkKDF10jH74VmsnQbs10T6DgNqCU+aCUx9Mz0Bp0zvD3yMVisBV6RRyK4usLmrIo/e6c0B/A0Axg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=ch/BFBWe; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="ch/BFBWe" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7ACD91E8D; Wed, 22 Apr 2026 11:46:02 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 197FD3F641; Wed, 22 Apr 2026 11:46:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1776883568; bh=YL9Q/CEimzmzvwqCzwcq+9U08GB6hZYu6L+QSbxPgrw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ch/BFBWebDovM5JHuimYfJaNKI9Po1y0ZhwIQ6leJBuyfIlDwYKANwoEMc46lZ5Ev v4fZKAit7uX3nqmR4VWwqePi9+0FE6G0isDwEx4RFVkccZyVEgPvPIlGRaQtKy9SzW WSMb0XZ1/GKDIraL5xbdmcKmc0+UY89GWDXJ3nyg= Date: Wed, 22 Apr 2026 19:46:01 +0100 From: Yeoreum Yun To: Mimi Zohar Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, roberto.sassu@huawei.com, dmitry.kasatkin@gmail.com, eric.snowberg@oracle.com, jarkko@kernel.org, jgg@ziepe.ca, sudeep.holla@kernel.org, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, noodles@meta.com, sebastianene@google.com Subject: Re: [RFC PATCH v2 1/4] security: ima: call ima_init() again at late_initcall_sync for defered TPM Message-ID: References: <20260422162449.1814615-1-yeoreum.yun@arm.com> <20260422162449.1814615-2-yeoreum.yun@arm.com> <6919248bdc85dac60277fa9d9c83d8bd258ca635.camel@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <6919248bdc85dac60277fa9d9c83d8bd258ca635.camel@linux.ibm.com> Hi Mimi, > On Wed, 2026-04-22 at 17:24 +0100, Yeoreum Yun wrote: > > To generate the boot_aggregate log in the IMA subsystem with TPM PCR values, > > the TPM driver must be built as built-in and > > must be probed before the IMA subsystem is initialized. > > > > However, when the TPM device operates over the FF-A protocol using > > the CRB interface, probing fails and returns -EPROBE_DEFER if > > the tpm_crb_ffa device — an FF-A device that provides the communication > > interface to the tpm_crb driver — has not yet been probed. > > > > 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. > > > > When this occurs, probing the TPM device is deferred. > > However, the deferred probe can happen after the IMA subsystem > > has already been initialized, since IMA initialization is performed > > during late_initcall, and deferred_probe_initcall() is performed > > at the same level. > > > > To resolve this, call ima_init() again at late_inicall_sync level > > so that let IMA not miss TPM PCR value when generating boot_aggregate > > log though TPM device presents in the system. > > > > Signed-off-by: Yeoreum Yun > > A lot of change for just detecting whether ima_init() is being called on > late_initcall or late_initcall_sync(), without any explanation for all the other > changes (e.g. ima_init_core). > > Please just limit the change to just calling ima_init() twice. My concern is that ima_update_policy_flags() will be called when ima_init() is deferred -- not initialised anything. though functionally, it might be okay however, I think ima_update_policy_flags() and notifier should work after ima_init() works logically. This change I think not much quite a lot. just wrapper ima_init() with ima_init_core() with some error handling. Am I missing something? > > > > --- > > include/linux/lsm_hooks.h | 2 + > > security/integrity/ima/ima.h | 4 +- > > security/integrity/ima/ima_init.c | 10 +++- > > security/integrity/ima/ima_main.c | 76 +++++++++++++++++++++++------ > > security/integrity/ima/ima_policy.c | 3 ++ > > security/lsm_init.c | 13 ++++- > > 6 files changed, 87 insertions(+), 21 deletions(-) > > > > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h > > index d48bf0ad26f4..88fe105b7f00 100644 > > --- a/include/linux/lsm_hooks.h > > +++ b/include/linux/lsm_hooks.h > > @@ -166,6 +166,7 @@ enum lsm_order { > > * @initcall_fs: LSM callback for fs_initcall setup, optional > > * @initcall_device: LSM callback for device_initcall() setup, optional > > * @initcall_late: LSM callback for late_initcall() setup, optional > > + * @initcall_late_sync: LSM callback for late_initcall_sync() setup, optional > > */ > > struct lsm_info { > > const struct lsm_id *id; > > @@ -181,6 +182,7 @@ struct lsm_info { > > int (*initcall_fs)(void); > > int (*initcall_device)(void); > > int (*initcall_late)(void); > > + int (*initcall_late_sync)(void); > > }; > > > > #define DEFINE_LSM(lsm) \ > > diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h > > index 89ebe98ffc5e..75ee7ad184d0 100644 > > --- a/security/integrity/ima/ima.h > > +++ b/security/integrity/ima/ima.h > > @@ -62,6 +62,8 @@ extern int ima_hash_algo_idx __ro_after_init; > > extern int ima_extra_slots __ro_after_init; > > extern struct ima_algo_desc *ima_algo_array __ro_after_init; > > > > +extern bool ima_initialised __ro_after_init; > > + > > extern int ima_appraise; > > extern struct tpm_chip *ima_tpm_chip; > > extern const char boot_aggregate_name[]; > > @@ -257,7 +259,7 @@ static inline void ima_measure_kexec_event(const char *event_name) {} > > extern bool ima_canonical_fmt; > > > > /* Internal IMA function definitions */ > > -int ima_init(void); > > +int ima_init(bool late); > > int ima_fs_init(void); > > int ima_add_template_entry(struct ima_template_entry *entry, int violation, > > const char *op, struct inode *inode, > > diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c > > index a2f34f2d8ad7..c28c71090ad2 100644 > > --- a/security/integrity/ima/ima_init.c > > +++ b/security/integrity/ima/ima_init.c > > @@ -115,13 +115,19 @@ void __init ima_load_x509(void) > > } > > #endif > > > > -int __init ima_init(void) > > +int __init ima_init(bool late) > > { > > int rc; > > > > ima_tpm_chip = tpm_default_chip(); > > - if (!ima_tpm_chip) > > + if (!ima_tpm_chip) { > > + if (!late) { > > + pr_info("Defer initialisation to the late_initcall_sync stage.\n"); > > + return -EPROBE_DEFER; > > + } > > + > > pr_info("No TPM chip found, activating TPM-bypass!\n"); > > + } > > > > rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA); > > if (rc) > > diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c > > index 1d6229b156fb..ac444ee600e2 100644 > > --- a/security/integrity/ima/ima_main.c > > +++ b/security/integrity/ima/ima_main.c > > @@ -38,6 +38,7 @@ int ima_appraise; > > #endif > > > > int __ro_after_init ima_hash_algo = HASH_ALGO_SHA1; > > +bool ima_initialised __ro_after_init = false; > > static int hash_setup_done; > > static int ima_disabled __ro_after_init; > > > > @@ -1237,6 +1238,35 @@ static int ima_kernel_module_request(char *kmod_name) > > > > #endif /* CONFIG_INTEGRITY_ASYMMETRIC_KEYS */ > > > > +static int __init init_ima_core(bool late) > > +{ > > + int err; > > + > > + if (ima_initialised) > > + return 0; > > + > > + err = ima_init(late); > > + if (err == -EPROBE_DEFER) > > + return 0; > > + > > + if (err && strcmp(hash_algo_name[ima_hash_algo], > > + CONFIG_IMA_DEFAULT_HASH) != 0) { > > + pr_info("Allocating %s failed, going to use default hash algorithm %s\n", > > + hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH); > > + hash_setup_done = 0; > > + hash_setup(CONFIG_IMA_DEFAULT_HASH); > > + err = ima_init(late); > > + } > > + > > + if (!err) { > > + ima_update_policy_flags(); > > + ima_initialised = true; > > + } else > > + ima_disabled = 1; > > + > > + return err; > > +} > > + > > static int __init init_ima(void) > > { > > int error; > > @@ -1250,30 +1280,42 @@ static int __init init_ima(void) > > ima_appraise_parse_cmdline(); > > ima_init_template_list(); > > hash_setup(CONFIG_IMA_DEFAULT_HASH); > > - error = ima_init(); > > - > > - if (error && strcmp(hash_algo_name[ima_hash_algo], > > - CONFIG_IMA_DEFAULT_HASH) != 0) { > > - pr_info("Allocating %s failed, going to use default hash algorithm %s\n", > > - hash_algo_name[ima_hash_algo], CONFIG_IMA_DEFAULT_HASH); > > - hash_setup_done = 0; > > - hash_setup(CONFIG_IMA_DEFAULT_HASH); > > - error = ima_init(); > > - } > > - > > - if (error) > > - return error; > > > > error = register_blocking_lsm_notifier(&ima_lsm_policy_notifier); > > - if (error) > > + if (error) { > > pr_warn("Couldn't register LSM notifier, error %d\n", error); > > + goto disable_ima; > > + } > > > > - if (!error) > > - ima_update_policy_flags(); > > + error = init_ima_core(false); > > + if (error) { > > + unregister_blocking_lsm_notifier(&ima_lsm_policy_notifier); > > + goto disable_ima; > > + } > > + > > + return 0; > > > > +disable_ima: > > + ima_disabled = 1; > > return error; > > } > > > > +static int __init late_init_ima(void) > > +{ > > + int err; > > + > > + if (ima_disabled) > > + return 0; > > + > > + err = init_ima_core(true); > > + if (err) { > > + unregister_blocking_lsm_notifier(&ima_lsm_policy_notifier); > > + ima_disabled = 1; > > + } > > + > > + return err; > > +} > > + > > static struct security_hook_list ima_hooks[] __ro_after_init = { > > LSM_HOOK_INIT(bprm_check_security, ima_bprm_check), > > LSM_HOOK_INIT(bprm_creds_for_exec, ima_bprm_creds_for_exec), > > @@ -1321,4 +1363,6 @@ DEFINE_LSM(ima) = { > > .blobs = &ima_blob_sizes, > > /* Start IMA after the TPM is available */ > > .initcall_late = init_ima, > > + /* Start IMA late in case of probing TPM is deferred. */ > > + .initcall_late_sync = late_init_ima, > > }; > > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > > index bf2d7ba4c14a..c3bcc3521c81 100644 > > --- a/security/integrity/ima/ima_policy.c > > +++ b/security/integrity/ima/ima_policy.c > > @@ -501,6 +501,9 @@ static void ima_lsm_update_rules(void) > > int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event, > > void *lsm_data) > > { > > + if (!ima_initialised) > > + return NOTIFY_DONE; > > + > > if (event != LSM_POLICY_CHANGE) > > return NOTIFY_DONE; > > > > diff --git a/security/lsm_init.c b/security/lsm_init.c > > index 573e2a7250c4..4e5c59beb82a 100644 > > --- a/security/lsm_init.c > > +++ b/security/lsm_init.c > > @@ -547,13 +547,22 @@ device_initcall(security_initcall_device); > > * security_initcall_late - Run the LSM late initcalls > > */ > > static int __init security_initcall_late(void) > > +{ > > + return lsm_initcall(late); > > +} > > +late_initcall(security_initcall_late); > > + > > +/** > > + * security_initcall_late_sync - Run the LSM late initcalls sync > > + */ > > +static int __init security_initcall_late_sync(void) > > { > > int rc; > > > > - rc = lsm_initcall(late); > > + rc = lsm_initcall(late_sync); > > lsm_pr_dbg("all enabled LSMs fully activated\n"); > > call_blocking_lsm_notifier(LSM_STARTED_ALL, NULL); > > > > return rc; > > } > > -late_initcall(security_initcall_late); > > +late_initcall_sync(security_initcall_late_sync); > > -- > > LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7} -- Sincerely, Yeoreum Yun