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Message-ID: <ecbe78fa-a032-e01d-2134-0dba8176ffba@digikod.net>
Date:   Fri, 4 Mar 2022 11:48:58 +0100
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To:     Casey Schaufler <casey@schaufler-ca.com>,
        casey.schaufler@intel.com, jmorris@namei.org,
        linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc:     linux-audit@redhat.com, keescook@chromium.org,
        john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
        paul@paul-moore.com, sds@tycho.nsa.gov,
        linux-kernel@vger.kernel.org
References: <20220202235323.23929-1-casey@schaufler-ca.com>
 <20220202235323.23929-4-casey@schaufler-ca.com>
From:   =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= <mic@digikod.net>
Subject: Re: [PATCH v32 03/28] LSM: Add the lsmblob data structure.
In-Reply-To: <20220202235323.23929-4-casey@schaufler-ca.com>
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On 03/02/2022 00:52, Casey Schaufler wrote:
> When more than one security module is exporting data to
> audit and networking sub-systems a single 32 bit integer
> is no longer sufficient to represent the data. Add a
> structure to be used instead.
> 
> The lsmblob structure is currently an array of
> u32 "secids". There is an entry for each of the
> security modules built into the system that would
> use secids if active. The system assigns the module
> a "slot" when it registers hooks. If modules are
> compiled in but not registered there will be unused
> slots.
> 
> A new lsm_id structure, which contains the name
> of the LSM and its slot number, is created. There
> is an instance for each LSM, which assigns the name
> and passes it to the infrastructure to set the slot.
> 
> The audit rules data is expanded to use an array of
> security module data rather than a single instance.
> A new structure audit_lsm_rules is defined to avoid the
> confusion which commonly accompanies the use of
> void ** parameters.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

Reviewed-by: Mickaël Salaün <mic@linux.microsoft.com>


Minor fixes:


> ---
>   include/linux/audit.h        | 10 ++++-
>   include/linux/lsm_hooks.h    | 12 +++++-
>   include/linux/security.h     | 74 +++++++++++++++++++++++++++++---
>   kernel/auditfilter.c         | 23 +++++-----
>   kernel/auditsc.c             | 17 +++-----
>   security/apparmor/lsm.c      |  7 ++-
>   security/bpf/hooks.c         | 12 +++++-
>   security/commoncap.c         |  7 ++-
>   security/landlock/cred.c     |  2 +-
>   security/landlock/fs.c       |  2 +-
>   security/landlock/ptrace.c   |  2 +-
>   security/landlock/setup.c    |  5 +++
>   security/landlock/setup.h    |  1 +
>   security/loadpin/loadpin.c   |  8 +++-
>   security/lockdown/lockdown.c |  7 ++-
>   security/safesetid/lsm.c     |  8 +++-
>   security/security.c          | 82 ++++++++++++++++++++++++++++++------
>   security/selinux/hooks.c     |  8 +++-
>   security/smack/smack_lsm.c   |  7 ++-
>   security/tomoyo/tomoyo.c     |  8 +++-
>   security/yama/yama_lsm.c     |  7 ++-
>   21 files changed, 253 insertions(+), 56 deletions(-)
> 
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index d06134ac6245..14849d5f84b4 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -11,6 +11,7 @@
>   
>   #include <linux/sched.h>
>   #include <linux/ptrace.h>
> +#include <linux/security.h>
>   #include <linux/audit_arch.h>
>   #include <uapi/linux/audit.h>
>   #include <uapi/linux/netfilter/nf_tables.h>
> @@ -59,6 +60,10 @@ struct audit_krule {
>   /* Flag to indicate legacy AUDIT_LOGINUID unset usage */
>   #define AUDIT_LOGINUID_LEGACY		0x1
>   
> +struct audit_lsm_rules {
> +	void	*rule[LSMBLOB_ENTRIES];
> +};
> +
>   struct audit_field {
>   	u32				type;
>   	union {
> @@ -66,8 +71,9 @@ struct audit_field {
>   		kuid_t			uid;
>   		kgid_t			gid;
>   		struct {
> -			char		*lsm_str;
> -			void		*lsm_rule;
> +			bool			lsm_isset;
> +			char			*lsm_str;
> +			struct audit_lsm_rules	lsm_rules;
>   		};
>   	};
>   	u32				op;
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index 129d99c6f9ed..2c2d0ef59a41 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -1582,6 +1582,14 @@ struct security_hook_heads {
>   	#undef LSM_HOOK
>   } __randomize_layout;
>   
> +/*
> + * Information that identifies a security module.
> + */
> +struct lsm_id {
> +	const char	*lsm;	/* Name of the LSM */
> +	int		slot;	/* Slot in lsmblob if one is allocated */
> +};
> +
>   /*
>    * Security module hook list structure.
>    * For use with generic list macros for common operations.
> @@ -1590,7 +1598,7 @@ struct security_hook_list {
>   	struct hlist_node		list;
>   	struct hlist_head		*head;
>   	union security_list_options	hook;
> -	char				*lsm;
> +	struct lsm_id			*lsmid;
>   } __randomize_layout;
>   
>   /*
> @@ -1626,7 +1634,7 @@ extern struct security_hook_heads security_hook_heads;
>   extern char *lsm_names;
>   
>   extern void security_add_hooks(struct security_hook_list *hooks, int count,
> -				char *lsm);
> +			       struct lsm_id *lsmid);
>   
>   #define LSM_FLAG_LEGACY_MAJOR	BIT(0)
>   #define LSM_FLAG_EXCLUSIVE	BIT(1)
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 33e0f2e659df..1a7e5bf36a82 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -39,6 +39,7 @@ struct kernel_siginfo;
>   struct sembuf;
>   struct kern_ipc_perm;
>   struct audit_context;
> +struct audit_lsm_rules;
>   struct super_block;
>   struct inode;
>   struct dentry;
> @@ -134,6 +135,65 @@ enum lockdown_reason {
>   
>   extern const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1];
>   
> +/*
> + * Data exported by the security modules
> + *
> + * Any LSM that provides secid or secctx based hooks must be included.
> + */
> +#define LSMBLOB_ENTRIES ( \
> +	(IS_ENABLED(CONFIG_SECURITY_SELINUX) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_SECURITY_SMACK) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_SECURITY_APPARMOR) ? 1 : 0) + \
> +	(IS_ENABLED(CONFIG_BPF_LSM) ? 1 : 0))
> +
> +struct lsmblob {
> +	u32     secid[LSMBLOB_ENTRIES];
> +};
> +
> +#define LSMBLOB_INVALID		-1	/* Not a valid LSM slot number */
> +#define LSMBLOB_NEEDED		-2	/* Slot requested on initialization */
> +#define LSMBLOB_NOT_NEEDED	-3	/* Slot not requested */
> +
> +/**
> + * lsmblob_init - initialize an lsmblob structure
> + * @blob: Pointer to the data to initialize
> + * @secid: The initial secid value
> + *
> + * Set all secid for all modules to the specified value.
> + */
> +static inline void lsmblob_init(struct lsmblob *blob, u32 secid)
> +{
> +	int i;
> +
> +	for (i = 0; i < LSMBLOB_ENTRIES; i++)
> +		blob->secid[i] = secid;
> +}
> +
> +/**
> + * lsmblob_is_set - report if there is an value in the lsmblob

*a* value


> + * @blob: Pointer to the exported LSM data
> + *
> + * Returns true if there is a secid set, false otherwise
> + */
> +static inline bool lsmblob_is_set(struct lsmblob *blob)
> +{
> +	struct lsmblob empty = {};

const struct lsmblob empty = {};

> +
> +	return !!memcmp(blob, &empty, sizeof(*blob));
> +}
> +
> +/**
> + * lsmblob_equal - report if the two lsmblob's are equal
> + * @bloba: Pointer to one LSM data
> + * @blobb: Pointer to the other LSM data
> + *
> + * Returns true if all entries in the two are equal, false otherwise
> + */
> +static inline bool lsmblob_equal(struct lsmblob *bloba, struct lsmblob *blobb)

const struct lsmblob *bloba, const struct lsmblob *blobb


> +{
> +	return !memcmp(bloba, blobb, sizeof(*bloba));
> +}
> +
>   /* These functions are in security/commoncap.c */
>   extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
>   		       int cap, unsigned int opts);
> @@ -1879,15 +1939,17 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer)
>   
>   #ifdef CONFIG_AUDIT
>   #ifdef CONFIG_SECURITY
> -int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule);
> +int security_audit_rule_init(u32 field, u32 op, char *rulestr,
> +			     struct audit_lsm_rules *lsmrules);
>   int security_audit_rule_known(struct audit_krule *krule);
> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule);
> -void security_audit_rule_free(void *lsmrule);
> +int security_audit_rule_match(u32 secid, u32 field, u32 op,
> +			      struct audit_lsm_rules *lsmrules);
> +void security_audit_rule_free(struct audit_lsm_rules *lsmrules);
>   
>   #else
>   
>   static inline int security_audit_rule_init(u32 field, u32 op, char *rulestr,
> -					   void **lsmrule)
> +					   struct audit_lsm_rules *lsmrules)
>   {
>   	return 0;
>   }
> @@ -1898,12 +1960,12 @@ static inline int security_audit_rule_known(struct audit_krule *krule)
>   }
>   
>   static inline int security_audit_rule_match(u32 secid, u32 field, u32 op,
> -					    void *lsmrule)
> +					    struct audit_lsm_rules *lsmrules)
>   {
>   	return 0;
>   }
>   
> -static inline void security_audit_rule_free(void *lsmrule)
> +static inline void security_audit_rule_free(struct audit_lsm_rules *lsmrules)
>   { }
>   
>   #endif /* CONFIG_SECURITY */
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 42d99896e7a6..de75bd6ad866 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -76,7 +76,7 @@ static void audit_free_lsm_field(struct audit_field *f)
>   	case AUDIT_OBJ_LEV_LOW:
>   	case AUDIT_OBJ_LEV_HIGH:
>   		kfree(f->lsm_str);
> -		security_audit_rule_free(f->lsm_rule);
> +		security_audit_rule_free(&f->lsm_rules);
>   	}
>   }
>   
> @@ -529,7 +529,7 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
>   			entry->rule.buflen += f_val;
>   			f->lsm_str = str;
>   			err = security_audit_rule_init(f->type, f->op, str,
> -						       (void **)&f->lsm_rule);
> +						       &f->lsm_rules);
>   			/* Keep currently invalid fields around in case they
>   			 * become valid after a policy reload. */
>   			if (err == -EINVAL) {
> @@ -782,7 +782,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
>   	return 0;
>   }
>   
> -/* Duplicate LSM field information.  The lsm_rule is opaque, so must be
> +/* Duplicate LSM field information.  The lsm_rules is opaque, so must be
>    * re-initialized. */
>   static inline int audit_dupe_lsm_field(struct audit_field *df,
>   					   struct audit_field *sf)
> @@ -796,9 +796,9 @@ static inline int audit_dupe_lsm_field(struct audit_field *df,
>   		return -ENOMEM;
>   	df->lsm_str = lsm_str;
>   
> -	/* our own (refreshed) copy of lsm_rule */
> +	/* our own (refreshed) copy of lsm_rules */
>   	ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
> -				       (void **)&df->lsm_rule);
> +				       &df->lsm_rules);
>   	/* Keep currently invalid fields around in case they
>   	 * become valid after a policy reload. */
>   	if (ret == -EINVAL) {
> @@ -850,7 +850,7 @@ struct audit_entry *audit_dupe_rule(struct audit_krule *old)
>   	new->tree = old->tree;
>   	memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
>   
> -	/* deep copy this information, updating the lsm_rule fields, because
> +	/* deep copy this information, updating the lsm_rules fields, because
>   	 * the originals will all be freed when the old rule is freed. */
>   	for (i = 0; i < fcount; i++) {
>   		switch (new->fields[i].type) {
> @@ -1367,10 +1367,11 @@ int audit_filter(int msgtype, unsigned int listtype)
>   			case AUDIT_SUBJ_TYPE:
>   			case AUDIT_SUBJ_SEN:
>   			case AUDIT_SUBJ_CLR:
> -				if (f->lsm_rule) {
> +				if (f->lsm_str) {
>   					security_current_getsecid_subj(&sid);
>   					result = security_audit_rule_match(sid,
> -						   f->type, f->op, f->lsm_rule);
> +						   f->type, f->op,
> +						   &f->lsm_rules);
>   				}
>   				break;
>   			case AUDIT_EXE:
> @@ -1397,7 +1398,7 @@ int audit_filter(int msgtype, unsigned int listtype)
>   	return ret;
>   }
>   
> -static int update_lsm_rule(struct audit_krule *r)
> +static int update_lsm_rules(struct audit_krule *r)
>   {
>   	struct audit_entry *entry = container_of(r, struct audit_entry, rule);
>   	struct audit_entry *nentry;
> @@ -1429,7 +1430,7 @@ static int update_lsm_rule(struct audit_krule *r)
>   	return err;
>   }
>   
> -/* This function will re-initialize the lsm_rule field of all applicable rules.
> +/* This function will re-initialize the lsm_rules field of all applicable rules.
>    * It will traverse the filter lists serarching for rules that contain LSM
>    * specific filter fields.  When such a rule is found, it is copied, the
>    * LSM field is re-initialized, and the old rule is replaced with the
> @@ -1444,7 +1445,7 @@ int audit_update_lsm_rules(void)
>   
>   	for (i = 0; i < AUDIT_NR_FILTERS; i++) {
>   		list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
> -			int res = update_lsm_rule(r);
> +			int res = update_lsm_rules(r);
>   			if (!err)
>   				err = res;
>   		}
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index fce5d43a933f..f1c26a322f9d 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -664,7 +664,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>   			   match for now to avoid losing information that
>   			   may be wanted.   An error message will also be
>   			   logged upon error */
> -			if (f->lsm_rule) {
> +			if (f->lsm_str) {
>   				if (need_sid) {
>   					/* @tsk should always be equal to
>   					 * @current with the exception of
> @@ -679,8 +679,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>   					need_sid = 0;
>   				}
>   				result = security_audit_rule_match(sid, f->type,
> -								   f->op,
> -								   f->lsm_rule);
> +							f->op, &f->lsm_rules);
>   			}
>   			break;
>   		case AUDIT_OBJ_USER:
> @@ -690,21 +689,19 @@ static int audit_filter_rules(struct task_struct *tsk,
>   		case AUDIT_OBJ_LEV_HIGH:
>   			/* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR
>   			   also applies here */
> -			if (f->lsm_rule) {
> +			if (f->lsm_str) {
>   				/* Find files that match */
>   				if (name) {
>   					result = security_audit_rule_match(
>   								name->osid,
>   								f->type,
>   								f->op,
> -								f->lsm_rule);
> +								&f->lsm_rules);
>   				} else if (ctx) {
>   					list_for_each_entry(n, &ctx->names_list, list) {
>   						if (security_audit_rule_match(
> -								n->osid,
> -								f->type,
> -								f->op,
> -								f->lsm_rule)) {
> +							n->osid, f->type, f->op,
> +							&f->lsm_rules)) {
>   							++result;
>   							break;
>   						}
> @@ -715,7 +712,7 @@ static int audit_filter_rules(struct task_struct *tsk,
>   					break;
>   				if (security_audit_rule_match(ctx->ipc.osid,
>   							      f->type, f->op,
> -							      f->lsm_rule))
> +							      &f->lsm_rules))
>   					++result;
>   			}
>   			break;
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index be8976c407f4..1e53fea61335 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -1168,6 +1168,11 @@ struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = {
>   	.lbs_sock = sizeof(struct aa_sk_ctx),
>   };
>   
> +static struct lsm_id apparmor_lsmid __lsm_ro_after_init = {
> +	.lsm  = "apparmor",
> +	.slot = LSMBLOB_NEEDED
> +};
> +
>   static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
>   	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
> @@ -1853,7 +1858,7 @@ static int __init apparmor_init(void)
>   		goto buffers_out;
>   	}
>   	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
> -				"apparmor");
> +				&apparmor_lsmid);
>   
>   	/* Report that AppArmor successfully initialized */
>   	apparmor_initialized = 1;
> diff --git a/security/bpf/hooks.c b/security/bpf/hooks.c
> index e5971fa74fd7..7a58fe9ab8c4 100644
> --- a/security/bpf/hooks.c
> +++ b/security/bpf/hooks.c
> @@ -15,9 +15,19 @@ static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(task_free, bpf_task_storage_free),
>   };
>   
> +/*
> + * slot has to be LSMBLOB_NEEDED because some of the hooks
> + * supplied by this module require a slot.
> + */
> +struct lsm_id bpf_lsmid __lsm_ro_after_init = {
> +	.lsm = "bpf",
> +	.slot = LSMBLOB_NEEDED
> +};
> +
>   static int __init bpf_lsm_init(void)
>   {
> -	security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks), "bpf");
> +	security_add_hooks(bpf_lsm_hooks, ARRAY_SIZE(bpf_lsm_hooks),
> +			   &bpf_lsmid);
>   	pr_info("LSM support for eBPF active\n");
>   	return 0;
>   }
> diff --git a/security/commoncap.c b/security/commoncap.c
> index 5fc8986c3c77..c94ec46e07ac 100644
> --- a/security/commoncap.c
> +++ b/security/commoncap.c
> @@ -1446,6 +1446,11 @@ int cap_mmap_file(struct file *file, unsigned long reqprot,
>   
>   #ifdef CONFIG_SECURITY
>   
> +static struct lsm_id capability_lsmid __lsm_ro_after_init = {
> +	.lsm  = "capability",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(capable, cap_capable),
>   	LSM_HOOK_INIT(settime, cap_settime),
> @@ -1470,7 +1475,7 @@ static struct security_hook_list capability_hooks[] __lsm_ro_after_init = {
>   static int __init capability_init(void)
>   {
>   	security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks),
> -				"capability");
> +			   &capability_lsmid);
>   	return 0;
>   }
>   
> diff --git a/security/landlock/cred.c b/security/landlock/cred.c
> index 6725af24c684..56b121d65436 100644
> --- a/security/landlock/cred.c
> +++ b/security/landlock/cred.c
> @@ -42,5 +42,5 @@ static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
>   __init void landlock_add_cred_hooks(void)
>   {
>   	security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
> -			LANDLOCK_NAME);
> +			&landlock_lsmid);
>   }
> diff --git a/security/landlock/fs.c b/security/landlock/fs.c
> index 97b8e421f617..319e90e9290c 100644
> --- a/security/landlock/fs.c
> +++ b/security/landlock/fs.c
> @@ -688,5 +688,5 @@ static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
>   __init void landlock_add_fs_hooks(void)
>   {
>   	security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
> -			LANDLOCK_NAME);
> +			&landlock_lsmid);
>   }
> diff --git a/security/landlock/ptrace.c b/security/landlock/ptrace.c
> index f55b82446de2..54ccf55a077a 100644
> --- a/security/landlock/ptrace.c
> +++ b/security/landlock/ptrace.c
> @@ -116,5 +116,5 @@ static struct security_hook_list landlock_hooks[] __lsm_ro_after_init = {
>   __init void landlock_add_ptrace_hooks(void)
>   {
>   	security_add_hooks(landlock_hooks, ARRAY_SIZE(landlock_hooks),
> -			LANDLOCK_NAME);
> +			&landlock_lsmid);
>   }
> diff --git a/security/landlock/setup.c b/security/landlock/setup.c
> index f8e8e980454c..759e00b9436c 100644
> --- a/security/landlock/setup.c
> +++ b/security/landlock/setup.c
> @@ -23,6 +23,11 @@ struct lsm_blob_sizes landlock_blob_sizes __lsm_ro_after_init = {
>   	.lbs_superblock = sizeof(struct landlock_superblock_security),
>   };
>   
> +struct lsm_id landlock_lsmid __lsm_ro_after_init = {
> +	.lsm = LANDLOCK_NAME,
> +	.slot = LSMBLOB_NOT_NEEDED,
> +};
> +
>   static int __init landlock_init(void)
>   {
>   	landlock_add_cred_hooks();
> diff --git a/security/landlock/setup.h b/security/landlock/setup.h
> index 1daffab1ab4b..38bce5b172dc 100644
> --- a/security/landlock/setup.h
> +++ b/security/landlock/setup.h
> @@ -14,5 +14,6 @@
>   extern bool landlock_initialized;
>   
>   extern struct lsm_blob_sizes landlock_blob_sizes;
> +extern struct lsm_id landlock_lsmid;
>   
>   #endif /* _SECURITY_LANDLOCK_SETUP_H */
> diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
> index b12f7d986b1e..b569f3bc170b 100644
> --- a/security/loadpin/loadpin.c
> +++ b/security/loadpin/loadpin.c
> @@ -192,6 +192,11 @@ static int loadpin_load_data(enum kernel_load_data_id id, bool contents)
>   	return loadpin_read_file(NULL, (enum kernel_read_file_id) id, contents);
>   }
>   
> +static struct lsm_id loadpin_lsmid __lsm_ro_after_init = {
> +	.lsm  = "loadpin",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static struct security_hook_list loadpin_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(sb_free_security, loadpin_sb_free_security),
>   	LSM_HOOK_INIT(kernel_read_file, loadpin_read_file),
> @@ -239,7 +244,8 @@ static int __init loadpin_init(void)
>   	pr_info("ready to pin (currently %senforcing)\n",
>   		enforce ? "" : "not ");
>   	parse_exclude();
> -	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin");
> +	security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks),
> +			   &loadpin_lsmid);
>   	return 0;
>   }
>   
> diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
> index 87cbdc64d272..4e24ea3f7b7e 100644
> --- a/security/lockdown/lockdown.c
> +++ b/security/lockdown/lockdown.c
> @@ -75,6 +75,11 @@ static struct security_hook_list lockdown_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(locked_down, lockdown_is_locked_down),
>   };
>   
> +static struct lsm_id lockdown_lsmid __lsm_ro_after_init = {
> +	.lsm = "lockdown",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static int __init lockdown_lsm_init(void)
>   {
>   #if defined(CONFIG_LOCK_DOWN_KERNEL_FORCE_INTEGRITY)
> @@ -83,7 +88,7 @@ static int __init lockdown_lsm_init(void)
>   	lock_kernel_down("Kernel configuration", LOCKDOWN_CONFIDENTIALITY_MAX);
>   #endif
>   	security_add_hooks(lockdown_hooks, ARRAY_SIZE(lockdown_hooks),
> -			   "lockdown");
> +			   &lockdown_lsmid);
>   	return 0;
>   }
>   
> diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c
> index 963f4ad9cb66..0c368950dc14 100644
> --- a/security/safesetid/lsm.c
> +++ b/security/safesetid/lsm.c
> @@ -241,6 +241,11 @@ static int safesetid_task_fix_setgid(struct cred *new,
>   	return -EACCES;
>   }
>   
> +static struct lsm_id safesetid_lsmid __lsm_ro_after_init = {
> +	.lsm  = "safesetid",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static struct security_hook_list safesetid_security_hooks[] = {
>   	LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid),
>   	LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid),
> @@ -250,7 +255,8 @@ static struct security_hook_list safesetid_security_hooks[] = {
>   static int __init safesetid_security_init(void)
>   {
>   	security_add_hooks(safesetid_security_hooks,
> -			   ARRAY_SIZE(safesetid_security_hooks), "safesetid");
> +			   ARRAY_SIZE(safesetid_security_hooks),
> +			   &safesetid_lsmid);
>   
>   	/* Report that SafeSetID successfully initialized */
>   	safesetid_initialized = 1;
> diff --git a/security/security.c b/security/security.c
> index f2d4b20613c8..2bf21c726ba0 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -345,6 +345,7 @@ static void __init ordered_lsm_init(void)
>   	init_debug("sock blob size       = %d\n", blob_sizes.lbs_sock);
>   	init_debug("superblock blob size = %d\n", blob_sizes.lbs_superblock);
>   	init_debug("task blob size       = %d\n", blob_sizes.lbs_task);
> +	init_debug("lsmblob size         = %zu\n", sizeof(struct lsmblob));
>   
>   	/*
>   	 * Create any kmem_caches needed for blobs
> @@ -472,21 +473,38 @@ static int lsm_append(const char *new, char **result)
>   	return 0;
>   }
>   
> +/*
> + * Current index to use while initializing the lsmblob secid list.
> + */
> +static int lsm_slot __lsm_ro_after_init;
> +
>   /**
>    * security_add_hooks - Add a modules hooks to the hook lists.
>    * @hooks: the hooks to add
>    * @count: the number of hooks to add
> - * @lsm: the name of the security module
> + * @lsmid: the identification information for the security module
>    *
>    * Each LSM has to register its hooks with the infrastructure.
> + * If the LSM is using hooks that export secids allocate a slot
> + * for it in the lsmblob.
>    */
>   void __init security_add_hooks(struct security_hook_list *hooks, int count,
> -				char *lsm)
> +			       struct lsm_id *lsmid)
>   {
>   	int i;
>   
> +	WARN_ON(!lsmid->slot || !lsmid->lsm);
> +
> +	if (lsmid->slot == LSMBLOB_NEEDED) {
> +		if (lsm_slot >= LSMBLOB_ENTRIES)
> +			panic("%s Too many LSMs registered.\n", __func__);
> +		lsmid->slot = lsm_slot++;
> +		init_debug("%s assigned lsmblob slot %d\n", lsmid->lsm,
> +			   lsmid->slot);
> +	}
> +
>   	for (i = 0; i < count; i++) {
> -		hooks[i].lsm = lsm;
> +		hooks[i].lsmid = lsmid;
>   		hlist_add_tail_rcu(&hooks[i].list, hooks[i].head);
>   	}
>   
> @@ -495,7 +513,7 @@ void __init security_add_hooks(struct security_hook_list *hooks, int count,
>   	 * and fix this up afterwards.
>   	 */
>   	if (slab_is_available()) {
> -		if (lsm_append(lsm, &lsm_names) < 0)
> +		if (lsm_append(lsmid->lsm, &lsm_names) < 0)
>   			panic("%s - Cannot get early memory.\n", __func__);
>   	}
>   }
> @@ -2075,7 +2093,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm, char *name,
>   	struct security_hook_list *hp;
>   
>   	hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
> -		if (lsm != NULL && strcmp(lsm, hp->lsm))
> +		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
>   			continue;
>   		return hp->hook.getprocattr(p, name, value);
>   	}
> @@ -2088,7 +2106,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>   	struct security_hook_list *hp;
>   
>   	hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
> -		if (lsm != NULL && strcmp(lsm, hp->lsm))
> +		if (lsm != NULL && strcmp(lsm, hp->lsmid->lsm))
>   			continue;
>   		return hp->hook.setprocattr(name, value, size);
>   	}
> @@ -2579,9 +2597,27 @@ int security_key_getsecurity(struct key *key, char **_buffer)
>   
>   #ifdef CONFIG_AUDIT
>   
> -int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule)
> +int security_audit_rule_init(u32 field, u32 op, char *rulestr,
> +			     struct audit_lsm_rules *lsmrules)
>   {
> -	return call_int_hook(audit_rule_init, 0, field, op, rulestr, lsmrule);
> +	struct security_hook_list *hp;
> +	bool one_is_good = false;
> +	int rc = 0;
> +	int trc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_init, list) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		trc = hp->hook.audit_rule_init(field, op, rulestr,
> +					&lsmrules->rule[hp->lsmid->slot]);
> +		if (trc == 0)
> +			one_is_good = true;
> +		else
> +			rc = trc;
> +	}
> +	if (one_is_good)
> +		return 0;
> +	return rc;
>   }
>   
>   int security_audit_rule_known(struct audit_krule *krule)
> @@ -2589,14 +2625,36 @@ int security_audit_rule_known(struct audit_krule *krule)
>   	return call_int_hook(audit_rule_known, 0, krule);
>   }
>   
> -void security_audit_rule_free(void *lsmrule)
> +void security_audit_rule_free(struct audit_lsm_rules *lsmrules)
>   {
> -	call_void_hook(audit_rule_free, lsmrule);
> +	struct security_hook_list *hp;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_free, list) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		if (lsmrules->rule[hp->lsmid->slot] == NULL)
> +			continue;
> +		hp->hook.audit_rule_free(lsmrules->rule[hp->lsmid->slot]);
> +	}
>   }
>   
> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule)
> +int security_audit_rule_match(u32 secid, u32 field, u32 op,
> +			      struct audit_lsm_rules *lsmrules)
>   {
> -	return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		if (lsmrules->rule[hp->lsmid->slot] == NULL)
> +			continue;
> +		rc = hp->hook.audit_rule_match(secid, field, op,
> +					&lsmrules->rule[hp->lsmid->slot]);
> +		if (rc)
> +			return rc;
> +	}
> +	return 0;
>   }
>   #endif /* CONFIG_AUDIT */
>   
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index dffde40d367e..d67bcd1aeaf5 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -7009,6 +7009,11 @@ static int selinux_uring_sqpoll(void)
>   }
>   #endif /* CONFIG_IO_URING */
>   
> +static struct lsm_id selinux_lsmid __lsm_ro_after_init = {
> +	.lsm  = "selinux",
> +	.slot = LSMBLOB_NEEDED
> +};
> +
>   /*
>    * IMPORTANT NOTE: When adding new hooks, please be careful to keep this order:
>    * 1. any hooks that don't belong to (2.) or (3.) below,
> @@ -7324,7 +7329,8 @@ static __init int selinux_init(void)
>   
>   	hashtab_cache_init();
>   
> -	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
> +	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks),
> +			   &selinux_lsmid);
>   
>   	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
>   		panic("SELinux: Unable to register AVC netcache callback\n");
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index d58b50006e79..ff832d47479f 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -4744,6 +4744,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = {
>   	.lbs_superblock = sizeof(struct superblock_smack),
>   };
>   
> +static struct lsm_id smack_lsmid __lsm_ro_after_init = {
> +	.lsm  = "smack",
> +	.slot = LSMBLOB_NEEDED
> +};
> +
>   static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
>   	LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
> @@ -4947,7 +4952,7 @@ static __init int smack_init(void)
>   	/*
>   	 * Register with LSM
>   	 */
> -	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
> +	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), &smack_lsmid);
>   	smack_enabled = 1;
>   
>   	pr_info("Smack:  Initializing.\n");
> diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c
> index b6a31901f289..e8f6bb9782c1 100644
> --- a/security/tomoyo/tomoyo.c
> +++ b/security/tomoyo/tomoyo.c
> @@ -521,6 +521,11 @@ static void tomoyo_task_free(struct task_struct *task)
>   	}
>   }
>   
> +static struct lsm_id tomoyo_lsmid __lsm_ro_after_init = {
> +	.lsm  = "tomoyo",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   /*
>    * tomoyo_security_ops is a "struct security_operations" which is used for
>    * registering TOMOYO.
> @@ -573,7 +578,8 @@ static int __init tomoyo_init(void)
>   	struct tomoyo_task *s = tomoyo_task(current);
>   
>   	/* register ourselves with the security framework */
> -	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo");
> +	security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks),
> +			   &tomoyo_lsmid);
>   	pr_info("TOMOYO Linux initialized\n");
>   	s->domain_info = &tomoyo_kernel_domain;
>   	atomic_inc(&tomoyo_kernel_domain.users);
> diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
> index 06e226166aab..a9639ea541f7 100644
> --- a/security/yama/yama_lsm.c
> +++ b/security/yama/yama_lsm.c
> @@ -421,6 +421,11 @@ static int yama_ptrace_traceme(struct task_struct *parent)
>   	return rc;
>   }
>   
> +static struct lsm_id yama_lsmid __lsm_ro_after_init = {
> +	.lsm  = "yama",
> +	.slot = LSMBLOB_NOT_NEEDED
> +};
> +
>   static struct security_hook_list yama_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(ptrace_access_check, yama_ptrace_access_check),
>   	LSM_HOOK_INIT(ptrace_traceme, yama_ptrace_traceme),
> @@ -477,7 +482,7 @@ static inline void yama_init_sysctl(void) { }
>   static int __init yama_init(void)
>   {
>   	pr_info("Yama: becoming mindful.\n");
> -	security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), "yama");
> +	security_add_hooks(yama_hooks, ARRAY_SIZE(yama_hooks), &yama_lsmid);
>   	yama_init_sysctl();
>   	return 0;
>   }