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// SPDX-License-Identifier: GPL-2.0-or-later/* * LSM initialization functions */ #define pr_fmt(fmt) "LSM: " fmt #include <linux/init.h>#include <linux/lsm_hooks.h> #include "lsm.h" /* LSM enabled constants. */static __initdata int lsm_enabled_true = 1;static __initdata int lsm_enabled_false = 0; /* Pointers to LSM sections defined in include/asm-generic/vmlinux.lds.h */extern struct lsm_info __start_lsm_info[], __end_lsm_info[];extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[]; /* Number of "early" LSMs */static __initdata unsigned int lsm_count_early; /* Build and boot-time LSM ordering. */static __initconst const char *const lsm_order_builtin = CONFIG_LSM;static __initdata const char *lsm_order_cmdline;static __initdata const char *lsm_order_legacy; /* Ordered list of LSMs to initialize. */static __initdata struct lsm_info *lsm_order[MAX_LSM_COUNT + 1];static __initdata struct lsm_info *lsm_exclusive; #define lsm_order_for_each(iter)					\	for ((iter) = lsm_order; *(iter); (iter)++)#define lsm_for_each_raw(iter)						\	for ((iter) = __start_lsm_info;					\	     (iter) < __end_lsm_info; (iter)++)#define lsm_early_for_each_raw(iter)					\	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 */static int __init lsm_choose_security(char *str){	lsm_order_legacy = str;	return 1;}__setup("security=", lsm_choose_security); /** * lsm_choose_lsm - Modern LSM selection * @str: kernel command line parameter */static int __init lsm_choose_lsm(char *str){	lsm_order_cmdline = str;	return 1;}__setup("lsm=", lsm_choose_lsm); /** * lsm_debug_enable - Enable LSM framework debugging * @str: kernel command line parameter * * Currently we only provide debug info during LSM initialization, but we may * want to expand this in the future. */static int __init lsm_debug_enable(char *str){	lsm_debug = true;	return 1;}__setup("lsm.debug", lsm_debug_enable); /** * lsm_enabled_set - Mark a LSM as enabled * @lsm: LSM definition * @enabled: enabled flag */static void __init lsm_enabled_set(struct lsm_info *lsm, bool enabled){	/*	 * When an LSM hasn't configured an enable variable, we can use	 * a hard-coded location for storing the default enabled state.	 */	if (!lsm->enabled ||	    lsm->enabled == &lsm_enabled_true ||	    lsm->enabled == &lsm_enabled_false) {		lsm->enabled = enabled ? &lsm_enabled_true : &lsm_enabled_false;	} else {		*lsm->enabled = enabled;	}} /** * lsm_is_enabled - Determine if a LSM is enabled * @lsm: LSM definition */static inline bool lsm_is_enabled(struct lsm_info *lsm){	return (lsm->enabled ? *lsm->enabled : false);} /** * lsm_order_exists - Determine if a LSM exists in the ordered list * @lsm: LSM definition */static bool __init lsm_order_exists(struct lsm_info *lsm){	struct lsm_info **check; 	lsm_order_for_each(check) {		if (*check == lsm)			return true;	} 	return false;} /** * lsm_order_append - Append a LSM to the ordered list * @lsm: LSM definition * @src: source of the addition * * Append @lsm to the enabled LSM array after ensuring that it hasn't been * explicitly disabled, is a duplicate entry, or would run afoul of the * LSM_FLAG_EXCLUSIVE logic. */static void __init lsm_order_append(struct lsm_info *lsm, const char *src){	/* Ignore duplicate selections. */	if (lsm_order_exists(lsm))		return; 	/* Skip explicitly disabled LSMs. */	if (lsm->enabled && !lsm_is_enabled(lsm)) {		lsm_pr_dbg("skip previously disabled LSM %s:%s\n",			   src, lsm->id->name);		return;	} 	if (lsm_active_cnt == MAX_LSM_COUNT) {		pr_warn("exceeded maximum LSM count on %s:%s\n",			src, lsm->id->name);		lsm_enabled_set(lsm, false);		return;	} 	if (lsm->flags & LSM_FLAG_EXCLUSIVE) {		if (lsm_exclusive) {			lsm_pr_dbg("skip exclusive LSM conflict %s:%s\n",				   src, lsm->id->name);			lsm_enabled_set(lsm, false);			return;		} else {			lsm_pr_dbg("select exclusive LSM %s:%s\n",				   src, lsm->id->name);			lsm_exclusive = lsm;		}	} 	lsm_enabled_set(lsm, true);	lsm_order[lsm_active_cnt] = lsm;	lsm_idlist[lsm_active_cnt++] = lsm->id; 	lsm_pr_dbg("enabling LSM %s:%s\n", src, lsm->id->name);} /** * lsm_order_parse - Parse the comma delimited LSM list * @list: LSM list * @src: source of the list */static void __init lsm_order_parse(const char *list, const char *src){	struct lsm_info *lsm;	char *sep, *name, *next; 	/* Handle any Legacy LSM exclusions if one was specified. */	if (lsm_order_legacy) {		/*		 * To match the original "security=" behavior, this explicitly		 * does NOT fallback to another Legacy Major if the selected		 * one was separately disabled: disable all non-matching		 * Legacy Major LSMs.		 */		lsm_for_each_raw(lsm) {			if ((lsm->flags & LSM_FLAG_LEGACY_MAJOR) &&			     strcmp(lsm->id->name, lsm_order_legacy)) {				lsm_enabled_set(lsm, false);				lsm_pr_dbg("skip legacy LSM conflict %s:%s\n",					   src, lsm->id->name);			}		}	} 	/* LSM_ORDER_FIRST */	lsm_for_each_raw(lsm) {		if (lsm->order == LSM_ORDER_FIRST)			lsm_order_append(lsm, "first");	} 	/* Normal or "mutable" LSMs */	sep = kstrdup(list, GFP_KERNEL);	next = sep;	/* Walk the list, looking for matching LSMs. */	while ((name = strsep(&next, ",")) != NULL) {		lsm_for_each_raw(lsm) {			if (!strcmp(lsm->id->name, name) &&			    lsm->order == LSM_ORDER_MUTABLE)				lsm_order_append(lsm, src);		}	}	kfree(sep); 	/* Legacy LSM if specified. */	if (lsm_order_legacy) {		lsm_for_each_raw(lsm) {			if (!strcmp(lsm->id->name, lsm_order_legacy))				lsm_order_append(lsm, src);		}	} 	/* LSM_ORDER_LAST */	lsm_for_each_raw(lsm) {		if (lsm->order == LSM_ORDER_LAST)			lsm_order_append(lsm, "last");	} 	/* Disable all LSMs not previously enabled. */	lsm_for_each_raw(lsm) {		if (lsm_order_exists(lsm))			continue;		lsm_enabled_set(lsm, false);		lsm_pr_dbg("skip disabled LSM %s:%s\n", src, lsm->id->name);	}} /** * lsm_blob_size_update - Update the LSM blob size and offset information * @sz_req: the requested additional blob size * @sz_cur: the existing blob size */static void __init lsm_blob_size_update(unsigned int *sz_req,					unsigned int *sz_cur){	unsigned int offset; 	if (*sz_req == 0)		return; 	offset = ALIGN(*sz_cur, sizeof(void *));	*sz_cur = offset + *sz_req;	*sz_req = offset;} /** * lsm_prepare - Prepare the LSM framework for a new LSM * @lsm: LSM definition */static void __init lsm_prepare(struct lsm_info *lsm){	struct lsm_blob_sizes *blobs = lsm->blobs; 	if (!blobs)		return; 	/* Register the LSM blob sizes. */	blobs = lsm->blobs;	lsm_blob_size_update(&blobs->lbs_cred, &blob_sizes.lbs_cred);	lsm_blob_size_update(&blobs->lbs_file, &blob_sizes.lbs_file);	lsm_blob_size_update(&blobs->lbs_backing_file,			     &blob_sizes.lbs_backing_file);	lsm_blob_size_update(&blobs->lbs_ib, &blob_sizes.lbs_ib);	/* inode blob gets an rcu_head in addition to LSM blobs. */	if (blobs->lbs_inode && blob_sizes.lbs_inode == 0)		blob_sizes.lbs_inode = sizeof(struct rcu_head);	lsm_blob_size_update(&blobs->lbs_inode, &blob_sizes.lbs_inode);	lsm_blob_size_update(&blobs->lbs_ipc, &blob_sizes.lbs_ipc);	lsm_blob_size_update(&blobs->lbs_key, &blob_sizes.lbs_key);	lsm_blob_size_update(&blobs->lbs_msg_msg, &blob_sizes.lbs_msg_msg);	lsm_blob_size_update(&blobs->lbs_perf_event,			     &blob_sizes.lbs_perf_event);	lsm_blob_size_update(&blobs->lbs_sock, &blob_sizes.lbs_sock);	lsm_blob_size_update(&blobs->lbs_superblock,			     &blob_sizes.lbs_superblock);	lsm_blob_size_update(&blobs->lbs_task, &blob_sizes.lbs_task);	lsm_blob_size_update(&blobs->lbs_tun_dev, &blob_sizes.lbs_tun_dev);	lsm_blob_size_update(&blobs->lbs_xattr_count,			     &blob_sizes.lbs_xattr_count);	lsm_blob_size_update(&blobs->lbs_bdev, &blob_sizes.lbs_bdev);	lsm_blob_size_update(&blobs->lbs_bpf_map, &blob_sizes.lbs_bpf_map);	lsm_blob_size_update(&blobs->lbs_bpf_prog, &blob_sizes.lbs_bpf_prog);	lsm_blob_size_update(&blobs->lbs_bpf_token, &blob_sizes.lbs_bpf_token);} /** * lsm_init_single - Initialize a given LSM * @lsm: LSM definition */static void __init lsm_init_single(struct lsm_info *lsm){	int ret; 	if (!lsm_is_enabled(lsm))		return; 	lsm_pr_dbg("initializing %s\n", lsm->id->name);	ret = lsm->init();	WARN(ret, "%s failed to initialize: %d\n", lsm->id->name, ret);} /** * lsm_static_call_init - Initialize a LSM's static calls * @hl: LSM hook list */static int __init lsm_static_call_init(struct security_hook_list *hl){	struct lsm_static_call *scall = hl->scalls;	int i; 	for (i = 0; i < MAX_LSM_COUNT; i++) {		/* Update the first static call that is not used yet */		if (!scall->hl) {			__static_call_update(scall->key, scall->trampoline,					     hl->hook.lsm_func_addr);			scall->hl = hl;			static_branch_enable(scall->active);			return 0;		}		scall++;	} 	return -ENOSPC;} /** * security_add_hooks - Add a LSM's hooks to the LSM framework's hook lists * @hooks: LSM hooks to add * @count: number of hooks to add * @lsmid: identification information for the LSM * * Each LSM has to register its hooks with the LSM framework. */void __init security_add_hooks(struct security_hook_list *hooks, int count,			       const struct lsm_id *lsmid){	int i; 	for (i = 0; i < count; i++) {		hooks[i].lsmid = lsmid;		if (lsm_static_call_init(&hooks[i]))			panic("exhausted LSM callback slots with LSM %s\n",			      lsmid->name);	}} /** * early_security_init - Initialize the early LSMs */int __init early_security_init(void){	struct lsm_info *lsm; 	/* NOTE: lsm_pr_dbg() doesn't work here as lsm_debug is not yet set */ 	lsm_early_for_each_raw(lsm) {		lsm_enabled_set(lsm, true);		lsm_order_append(lsm, "early");		lsm_prepare(lsm);		lsm_init_single(lsm);		lsm_count_early++;	} 	return 0;} /** * security_init - Initializes the LSM framework * * This should be called early in the kernel initialization sequence. */int __init security_init(void){	unsigned int cnt;	struct lsm_info **lsm; 	if (lsm_debug) {		struct lsm_info *i; 		cnt = 0;		lsm_pr("available LSMs: ");		lsm_early_for_each_raw(i)			lsm_pr_cont("%s%s(E)", (cnt++ ? "," : ""), i->id->name);		lsm_for_each_raw(i)			lsm_pr_cont("%s%s", (cnt++ ? "," : ""), i->id->name);		lsm_pr_cont("\n"); 		lsm_pr("built-in LSM config: %s\n", lsm_order_builtin); 		lsm_pr("legacy LSM parameter: %s\n", lsm_order_legacy);		lsm_pr("boot LSM parameter: %s\n", lsm_order_cmdline); 		/* see the note about lsm_pr_dbg() in early_security_init() */		lsm_early_for_each_raw(i)			lsm_pr("enabled LSM early:%s\n", i->id->name);	} 	if (lsm_order_cmdline) {		if (lsm_order_legacy)			lsm_order_legacy = NULL;		lsm_order_parse(lsm_order_cmdline, "cmdline");	} else		lsm_order_parse(lsm_order_builtin, "builtin"); 	lsm_order_for_each(lsm)		lsm_prepare(*lsm); 	if (lsm_debug) {		lsm_pr("blob(cred) size %d\n", blob_sizes.lbs_cred);		lsm_pr("blob(file) size %d\n", blob_sizes.lbs_file);		lsm_pr("blob(backing_file) size %d\n",		       blob_sizes.lbs_backing_file);		lsm_pr("blob(ib) size %d\n", blob_sizes.lbs_ib);		lsm_pr("blob(inode) size %d\n", blob_sizes.lbs_inode);		lsm_pr("blob(ipc) size %d\n", blob_sizes.lbs_ipc);		lsm_pr("blob(key) size %d\n", blob_sizes.lbs_key);		lsm_pr("blob(msg_msg)_size %d\n", blob_sizes.lbs_msg_msg);		lsm_pr("blob(sock) size %d\n", blob_sizes.lbs_sock);		lsm_pr("blob(superblock) size %d\n", blob_sizes.lbs_superblock);		lsm_pr("blob(perf_event) size %d\n", blob_sizes.lbs_perf_event);		lsm_pr("blob(task) size %d\n", blob_sizes.lbs_task);		lsm_pr("blob(tun_dev) size %d\n", blob_sizes.lbs_tun_dev);		lsm_pr("blob(xattr) count %d\n", blob_sizes.lbs_xattr_count);		lsm_pr("blob(bdev) size %d\n", blob_sizes.lbs_bdev);		lsm_pr("blob(bpf_map) size %d\n", blob_sizes.lbs_bpf_map);		lsm_pr("blob(bpf_prog) size %d\n", blob_sizes.lbs_bpf_prog);		lsm_pr("blob(bpf_token) size %d\n", blob_sizes.lbs_bpf_token);	} 	if (blob_sizes.lbs_file)		lsm_file_cache = kmem_cache_create("lsm_file_cache",						   blob_sizes.lbs_file, 0,						   SLAB_PANIC, NULL);	if (blob_sizes.lbs_backing_file)		lsm_backing_file_cache = kmem_cache_create(						   "lsm_backing_file_cache",						   blob_sizes.lbs_backing_file,						   0, SLAB_PANIC, NULL);	if (blob_sizes.lbs_inode)		lsm_inode_cache = kmem_cache_create("lsm_inode_cache",						    blob_sizes.lbs_inode, 0,						    SLAB_PANIC, NULL); 	if (lsm_cred_alloc((struct cred *)unrcu_pointer(current->cred),			   GFP_KERNEL))		panic("early LSM cred alloc failed\n");	if (lsm_task_alloc(current))		panic("early LSM task alloc failed\n"); 	cnt = 0;	lsm_order_for_each(lsm) {		/* skip the "early" LSMs as they have already been setup */		if (cnt++ < lsm_count_early)			continue;		lsm_init_single(*lsm);	} 	return 0;} /** * security_initcall_pure - Run the LSM pure initcalls */static int __init security_initcall_pure(void){

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