From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BC291EB18E; Wed, 9 Apr 2025 21:16:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744233403; cv=none; b=b8Le6qUrx8uedKkFLtBlcocOm82efjDmoBo6wAOPbzX0W6VWDO0z7hU+Cg1C4eINFArciA/fdy/SokmeuczUecehH+mx3pOJJ+Fw+CtmpMmzcVI8WkgezF9DLWZRCcJAcdp1zSxE1mhThkle15BVfh+O9UVHWOf7LwkUsFNbjn8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744233403; c=relaxed/simple; bh=+mqY8nLH6ozGdqw3+Rz1yDdpQlH+FIoOnuqVmEWUUKg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=JPKV++mFZTQAR7XYKKAEeosVzaEgnDkL3AjvWD2uBShaCIE2I10WrWd+s9u/bH9S4NsjIH3zkvp5VrQPCa7Jcefw/ze7YunTm1BQT/AdYPe0RTJstBbjMoHjQ1a+SMT38YuZk1cNC47EFcOHHL2QUFVsEzO2eTlu/3kuQfd7aFo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cmy2FGnt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Cmy2FGnt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5676C4CEE2; Wed, 9 Apr 2025 21:16:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744233400; bh=+mqY8nLH6ozGdqw3+Rz1yDdpQlH+FIoOnuqVmEWUUKg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Cmy2FGnt6RKSBHp4nugrmO9gaL8uU4BZZ9jzoA4Q3c5pFLY7cH+FYbqi6JvwvynVw lKoldyDhh0N9qLdoOoCbirFU8fqGZOYT7l6kR1HfNHDuiVPjJoklen5ODet5DrXTjw 5kCM5Ue770pRo4CmfWREuEyUIgXZaA+qN3opRyY9/Rz17VA2j0o+zUg7GCVwz7O7qZ 2BCkielMJBleKdBy669h6JXRvmTDLu1uyvdBV4xW5KZNBh2nWCMSrG1W3qciPa146V McrRweZgLnrnaLHMpJPXyzdIB3qJV1pqo9AaMKp8l8dPzGmPI9lMJIT4zZXYAcz62Q 2ochW06DTuLMA== Date: Wed, 9 Apr 2025 14:16:37 -0700 From: Kees Cook To: Paul Moore Cc: linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, John Johansen , Mimi Zohar , Roberto Sassu , Fan Wu , =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= , =?iso-8859-1?Q?G=FCnther?= Noack , Micah Morton , Casey Schaufler , Tetsuo Handa Subject: Re: [RFC PATCH 17/29] lsm: introduce an initcall mechanism into the LSM framework Message-ID: <202504091406.0A86DE05@keescook> References: <20250409185019.238841-31-paul@paul-moore.com> <20250409185019.238841-48-paul@paul-moore.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=us-ascii Content-Disposition: inline In-Reply-To: <20250409185019.238841-48-paul@paul-moore.com> On Wed, Apr 09, 2025 at 02:50:02PM -0400, Paul Moore wrote: > Currently the individual LSMs register their own initcalls, and while > this should be harmless, it can be wasteful in the case where a LSM > is disabled at boot as the initcall will still be executed. This > patch introduces support for managing the initcalls in the LSM > framework, and future patches will convert the existing LSMs over to > this new mechanism. > > Only initcall types which are used by the current in-tree LSMs are > supported, additional initcall types can easily be added in the future > if needed. > > Signed-off-by: Paul Moore > --- > include/linux/lsm_hooks.h | 33 ++++++++++++--- > security/lsm_init.c | 89 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 117 insertions(+), 5 deletions(-) > > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h > index a7ecb0791a0f..0d2c2a017ffc 100644 > --- a/include/linux/lsm_hooks.h > +++ b/include/linux/lsm_hooks.h > @@ -148,13 +148,36 @@ enum lsm_order { > LSM_ORDER_LAST = 1, /* This is only for integrity. */ > }; > > +/** > + * struct lsm_info - Define an individual LSM for the LSM framework. > + * @id: LSM name/ID info > + * @order: ordering with respect to other LSMs, optional > + * @flags: descriptive flags, optional > + * @blobs: LSM blob sharing, optional > + * @enabled: controlled by CONFIG_LSM, optional > + * @init: LSM specific initialization routine > + * @initcall_pure: LSM callback for initcall_pure() setup, optional > + * @initcall_early: LSM callback for early_initcall setup, optional > + * @initcall_core: LSM callback for core_initcall() setup, optional > + * @initcall_subsys: LSM callback for subsys_initcall() setup, optional > + * @initcall_fs: LSM callback for fs_initcall setup, optional > + * @nitcall_device: LSM callback for device_initcall() setup, optional > + * @initcall_late: LSM callback for late_initcall() setup, optional > + */ Yay! Proper kerndoc. :) > struct lsm_info { > const struct lsm_id *id; > - enum lsm_order order; /* Optional: default is LSM_ORDER_MUTABLE */ > - unsigned long flags; /* Optional: flags describing LSM */ > - int *enabled; /* Optional: controlled by CONFIG_LSM */ > - int (*init)(void); /* Required. */ > - struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */ > + enum lsm_order order; > + unsigned long flags; > + struct lsm_blob_sizes *blobs; > + int *enabled; > + int (*init)(void); > + int (*initcall_pure)(void); > + int (*initcall_early)(void); > + int (*initcall_core)(void); > + int (*initcall_subsys)(void); > + int (*initcall_fs)(void); > + int (*initcall_device)(void); > + int (*initcall_late)(void); > }; > > #define DEFINE_LSM(lsm) \ > diff --git a/security/lsm_init.c b/security/lsm_init.c > index 8e00afeb84cf..75eb0cc82869 100644 > --- a/security/lsm_init.c > +++ b/security/lsm_init.c > @@ -39,6 +39,27 @@ static __initdata struct lsm_info *lsm_order[MAX_LSM_COUNT + 1]; > for ((iter) = __start_early_lsm_info; \ > (iter) < __end_early_lsm_info; (iter)++) > > +#define lsm_initcall(level) \ > + ({ \ > + int _r, _rc = 0; \ > + struct lsm_info **_lp, *_l; \ > + lsm_order_for_each(_lp) { \ > + _l = *_lp; \ > + if (!_l->initcall_##level) \ > + continue; \ > + lsm_pr_dbg("running %s %s initcall", \ > + _l->id->name, #level); \ > + _r = _l->initcall_##level(); \ > + if (_r) { \ > + pr_warn("failed LSM %s %s initcall with errno %d\n", \ > + _l->id->name, #level, _r); \ > + if (!_rc) \ > + _rc = _r; \ > + } \ > + } \ > + _rc; \ > + }) > + > /** > * lsm_choose_security - Legacy "major" LSM selection > * @str: kernel command line parameter > @@ -458,3 +479,71 @@ int __init security_init(void) > > return 0; > } > + > +/** > + * security_initcall_pure - Run the LSM pure initcalls > + */ > +static int __init security_initcall_pure(void) > +{ > + return lsm_initcall(pure); > +} > +pure_initcall(security_initcall_pure); > + > +/** > + * security_initcall_early - Run the LSM early initcalls > + */ > +static int __init security_initcall_early(void) > +{ > + return lsm_initcall(early); > +} > +early_initcall(security_initcall_early); > + > +/** > + * security_initcall_core - Run the LSM core initcalls > + */ > +static int __init security_initcall_core(void) > +{ > + return lsm_initcall(core); > +} > +core_initcall(security_initcall_core); > + > +/** > + * security_initcall_subsys - Run the LSM subsys initcalls > + */ > +static int __init security_initcall_subsys(void) > +{ > + return lsm_initcall(subsys); > +} > +subsys_initcall(security_initcall_subsys); > + > +/** > + * security_initcall_fs - Run the LSM fs initcalls > + */ > +static int __init security_initcall_fs(void) > +{ > + return lsm_initcall(fs); > +} > +fs_initcall(security_initcall_fs); > + > +/** > + * security_initcall_device - Run the LSM device initcalls > + */ > +static int __init security_initcall_device(void) > +{ > + return lsm_initcall(device); > +} > +device_initcall(security_initcall_device); > + > +/** > + * security_initcall_late - Run the LSM late initcalls > + */ > +static int __init security_initcall_late(void) > +{ > + int rc; > + > + rc = lsm_initcall(late); > + lsm_pr_dbg("all enabled LSMs fully activated\n"); > + > + return rc; > +} > +late_initcall(security_initcall_late); You'd need a new place for the lsm_pr_dbg, but these are all just copy/paste. These could be macro-ified too? #define define_lsm_initcall(level) \ static int __init security_initcall_##level(void) \ { \ return lsm_initcall(level); \ } \ level##_initcall(security_initcall_##level) define_lsm_initcall(pure); define_lsm_initcall(early); define_lsm_initcall(core); define_lsm_initcall(subsys); define_lsm_initcall(fs); define_lsm_initcall(device); define_lsm_initcall(late); I'm not sure exposing the kerndoc for them is worth open-coding them? And, actually, it's just a macro calling a macro. You could just combine them? i.e. turn lsm_initcall() into: #define define_lsm_initcall(level) \ static int __init security_initcall_##level(void) \ { \ int _r, _rc = 0; \ struct lsm_info **_lp, *_l; \ ... return _rc; \ } \ level##_initcall(security_initcall_##level) But, I like it either way. Reviewed-by: Kees Cook -- Kees Cook