diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 0c908c091a03..dd33666567bc 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -2027,6 +2027,13 @@ struct security_hook_list { char *lsm; } __randomize_layout; +/* + * Security blob size or offset data. + */ +struct lsm_blob_sizes { + int lbs_cred; +}; + /* * Initializing a security_hook_list structure takes * up a lot of space in a source file. This macro takes @@ -2056,6 +2063,7 @@ struct lsm_info { 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. */ }; extern struct lsm_info __start_lsm_info[], __end_lsm_info[]; @@ -2095,4 +2103,8 @@ static inline void security_delete_hooks(struct security_hook_list *hooks, #define __lsm_ro_after_init __ro_after_init #endif /* CONFIG_SECURITY_WRITABLE_HOOKS */ +#ifdef CONFIG_SECURITY +void __init lsm_early_cred(struct cred *cred); +#endif + #endif /* ! __LINUX_LSM_HOOKS_H */ diff --git a/security/apparmor/include/cred.h b/security/apparmor/include/cred.h index a757370f2a0c..b9504a05fddc 100644 --- a/security/apparmor/include/cred.h +++ b/security/apparmor/include/cred.h @@ -25,7 +25,7 @@ static inline struct aa_label *cred_label(const struct cred *cred) { - struct aa_label **blob = cred->security; + struct aa_label **blob = cred->security + apparmor_blob_sizes.lbs_cred; AA_BUG(!blob); return *blob; @@ -34,7 +34,7 @@ static inline struct aa_label *cred_label(const struct cred *cred) static inline void set_cred_label(const struct cred *cred, struct aa_label *label) { - struct aa_label **blob = cred->security; + struct aa_label **blob = cred->security + apparmor_blob_sizes.lbs_cred; AA_BUG(!blob); *blob = label; diff --git a/security/apparmor/include/lib.h b/security/apparmor/include/lib.h index 6505e1ad9e23..bbe9b384d71d 100644 --- a/security/apparmor/include/lib.h +++ b/security/apparmor/include/lib.h @@ -16,6 +16,7 @@ #include #include +#include #include "match.h" @@ -55,6 +56,9 @@ const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name, size_t *ns_len); void aa_info_message(const char *str); +/* Security blob offsets */ +extern struct lsm_blob_sizes apparmor_blob_sizes; + /** * aa_strneq - compare null terminated @str to a non null terminated substring * @str: a null terminated string diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 8c2cb4b1a6c3..d5e4a384f205 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1151,6 +1151,13 @@ static int apparmor_inet_conn_request(struct sock *sk, struct sk_buff *skb, } #endif +/* + * The cred blob is a pointer to, not an instance of, an aa_task_ctx. + */ +struct lsm_blob_sizes apparmor_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct aa_task_ctx *), +}; + 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), @@ -1485,6 +1492,7 @@ static int __init set_init_ctx(void) if (!ctx) return -ENOMEM; + lsm_early_cred(cred); set_cred_label(cred, aa_get_label(ns_unconfined(root_ns))); task_ctx(current) = ctx; @@ -1725,5 +1733,6 @@ DEFINE_LSM(apparmor) = { .name = "apparmor", .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, .enabled = &apparmor_enabled, + .blobs = &apparmor_blob_sizes, .init = apparmor_init, }; diff --git a/security/security.c b/security/security.c index 60b39db95c2f..09be8ce007a2 100644 --- a/security/security.c +++ b/security/security.c @@ -41,6 +41,8 @@ struct security_hook_heads security_hook_heads __lsm_ro_after_init; static ATOMIC_NOTIFIER_HEAD(lsm_notifier_chain); char *lsm_names; +static struct lsm_blob_sizes blob_sizes __lsm_ro_after_init; + /* Boot-time LSM user choice */ static __initdata const char *chosen_lsm_order; static __initdata const char *chosen_major_lsm; @@ -139,6 +141,25 @@ static bool __init lsm_allowed(struct lsm_info *lsm) return true; } +static void __init lsm_set_blob_size(int *need, int *lbs) +{ + int offset; + + if (*need > 0) { + offset = *lbs; + *lbs += *need; + *need = offset; + } +} + +static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed) +{ + if (!needed) + return; + + lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred); +} + /* Prepare LSM for initialization. */ static void __init prepare_lsm(struct lsm_info *lsm) { @@ -153,6 +174,8 @@ static void __init prepare_lsm(struct lsm_info *lsm) exclusive = lsm; init_debug("exclusive chosen: %s\n", lsm->name); } + + lsm_set_blob_sizes(lsm->blobs); } } @@ -255,6 +278,8 @@ static void __init ordered_lsm_init(void) for (lsm = ordered_lsms; *lsm; lsm++) prepare_lsm(*lsm); + init_debug("cred blob size = %d\n", blob_sizes.lbs_cred); + for (lsm = ordered_lsms; *lsm; lsm++) initialize_lsm(*lsm); @@ -382,6 +407,47 @@ int unregister_lsm_notifier(struct notifier_block *nb) } EXPORT_SYMBOL(unregister_lsm_notifier); +/** + * lsm_cred_alloc - allocate a composite cred blob + * @cred: the cred that needs a blob + * @gfp: allocation type + * + * Allocate the cred blob for all the modules + * + * Returns 0, or -ENOMEM if memory can't be allocated. + */ +static int lsm_cred_alloc(struct cred *cred, gfp_t gfp) +{ + if (blob_sizes.lbs_cred == 0) { + cred->security = NULL; + return 0; + } + + cred->security = kzalloc(blob_sizes.lbs_cred, gfp); + if (cred->security == NULL) + return -ENOMEM; + return 0; +} + +/** + * lsm_early_cred - during initialization allocate a composite cred blob + * @cred: the cred that needs a blob + * + * Allocate the cred blob for all the modules if it's not already there + */ +void __init lsm_early_cred(struct cred *cred) +{ + int rc; + + if (cred == NULL) + panic("%s: NULL cred.\n", __func__); + if (cred->security != NULL) + return; + rc = lsm_cred_alloc(cred, GFP_KERNEL); + if (rc) + panic("%s: Early cred alloc failed.\n", __func__); +} + /* * Hook list operation macros. * @@ -1195,17 +1261,36 @@ void security_task_free(struct task_struct *task) int security_cred_alloc_blank(struct cred *cred, gfp_t gfp) { - return call_int_hook(cred_alloc_blank, 0, cred, gfp); + int rc = lsm_cred_alloc(cred, gfp); + + if (rc) + return rc; + + rc = call_int_hook(cred_alloc_blank, 0, cred, gfp); + if (rc) + security_cred_free(cred); + return rc; } void security_cred_free(struct cred *cred) { call_void_hook(cred_free, cred); + + kfree(cred->security); + cred->security = NULL; } int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp) { - return call_int_hook(cred_prepare, 0, new, old, gfp); + int rc = lsm_cred_alloc(new, gfp); + + if (rc) + return rc; + + rc = call_int_hook(cred_prepare, 0, new, old, gfp); + if (rc) + security_cred_free(new); + return rc; } void security_transfer_creds(struct cred *new, const struct cred *old) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 169cf5b3334b..239b13b442e7 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -210,12 +210,9 @@ static void cred_init_security(void) struct cred *cred = (struct cred *) current->real_cred; struct task_security_struct *tsec; - tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); - if (!tsec) - panic("SELinux: Failed to initialize initial task.\n"); - + lsm_early_cred(cred); + tsec = selinux_cred(cred); tsec->osid = tsec->sid = SECINITSID_KERNEL; - cred->security = tsec; } /* @@ -3685,47 +3682,16 @@ static int selinux_task_alloc(struct task_struct *task, sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL); } -/* - * allocate the SELinux part of blank credentials - */ -static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) -{ - struct task_security_struct *tsec; - - tsec = kzalloc(sizeof(struct task_security_struct), gfp); - if (!tsec) - return -ENOMEM; - - cred->security = tsec; - return 0; -} - -/* - * detach and free the LSM part of a set of credentials - */ -static void selinux_cred_free(struct cred *cred) -{ - struct task_security_struct *tsec = selinux_cred(cred); - - kfree(tsec); -} - /* * prepare a new set of credentials for modification */ static int selinux_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp) { - const struct task_security_struct *old_tsec; - struct task_security_struct *tsec; + const struct task_security_struct *old_tsec = selinux_cred(old); + struct task_security_struct *tsec = selinux_cred(new); - old_tsec = selinux_cred(old); - - tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); - if (!tsec) - return -ENOMEM; - - new->security = tsec; + *tsec = *old_tsec; return 0; } @@ -6678,6 +6644,10 @@ static void selinux_bpf_prog_free(struct bpf_prog_aux *aux) } #endif +struct lsm_blob_sizes selinux_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct task_security_struct), +}; + static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr), LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction), @@ -6761,8 +6731,6 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(file_open, selinux_file_open), LSM_HOOK_INIT(task_alloc, selinux_task_alloc), - LSM_HOOK_INIT(cred_alloc_blank, selinux_cred_alloc_blank), - LSM_HOOK_INIT(cred_free, selinux_cred_free), LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare), LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer), LSM_HOOK_INIT(cred_getsecid, selinux_cred_getsecid), @@ -6981,6 +6949,7 @@ DEFINE_LSM(selinux) = { .name = "selinux", .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, .enabled = &selinux_enabled, + .blobs = &selinux_blob_sizes, .init = selinux_init, }; diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 734b6833bdff..c2974b031d05 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -25,6 +25,7 @@ #include #include #include +#include #include #include "flask.h" #include "avc.h" @@ -158,9 +159,10 @@ struct bpf_security_struct { u32 sid; /*SID of bpf obj creater*/ }; +extern struct lsm_blob_sizes selinux_blob_sizes; static inline struct task_security_struct *selinux_cred(const struct cred *cred) { - return cred->security; + return cred->security + selinux_blob_sizes.lbs_cred; } #endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/smack/smack.h b/security/smack/smack.h index 01a922856eba..b27eb252e953 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -336,6 +336,7 @@ extern struct smack_known *smack_syslog_label; extern struct smack_known *smack_unconfined; #endif extern int smack_ptrace_rule; +extern struct lsm_blob_sizes smack_blob_sizes; extern struct smack_known smack_known_floor; extern struct smack_known smack_known_hat; @@ -358,7 +359,7 @@ extern struct hlist_head smack_known_hash[SMACK_HASH_SLOTS]; static inline struct task_smack *smack_cred(const struct cred *cred) { - return cred->security; + return cred->security + smack_blob_sizes.lbs_cred; } /* diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 9a050ca17296..bad27a8e1631 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -326,29 +326,20 @@ static struct inode_smack *new_inode_smack(struct smack_known *skp) } /** - * new_task_smack - allocate a task security blob + * init_task_smack - initialize a task security blob + * @tsp: blob to initialize * @task: a pointer to the Smack label for the running task * @forked: a pointer to the Smack label for the forked task - * @gfp: type of the memory for the allocation * - * Returns the new blob or NULL if there's no memory available */ -static struct task_smack *new_task_smack(struct smack_known *task, - struct smack_known *forked, gfp_t gfp) +static void init_task_smack(struct task_smack *tsp, struct smack_known *task, + struct smack_known *forked) { - struct task_smack *tsp; - - tsp = kzalloc(sizeof(struct task_smack), gfp); - if (tsp == NULL) - return NULL; - tsp->smk_task = task; tsp->smk_forked = forked; INIT_LIST_HEAD(&tsp->smk_rules); INIT_LIST_HEAD(&tsp->smk_relabel); mutex_init(&tsp->smk_rules_lock); - - return tsp; } /** @@ -1881,14 +1872,7 @@ static int smack_file_open(struct file *file) */ static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp) { - struct task_smack *tsp; - - tsp = new_task_smack(NULL, NULL, gfp); - if (tsp == NULL) - return -ENOMEM; - - cred->security = tsp; - + init_task_smack(smack_cred(cred), NULL, NULL); return 0; } @@ -1905,10 +1889,6 @@ static void smack_cred_free(struct cred *cred) struct list_head *l; struct list_head *n; - if (tsp == NULL) - return; - cred->security = NULL; - smk_destroy_label_list(&tsp->smk_relabel); list_for_each_safe(l, n, &tsp->smk_rules) { @@ -1916,7 +1896,6 @@ static void smack_cred_free(struct cred *cred) list_del(&rp->list); kfree(rp); } - kfree(tsp); } /** @@ -1931,14 +1910,10 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp) { struct task_smack *old_tsp = smack_cred(old); - struct task_smack *new_tsp; + struct task_smack *new_tsp = smack_cred(new); int rc; - new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp); - if (new_tsp == NULL) - return -ENOMEM; - - new->security = new_tsp; + init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task); rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp); if (rc != 0) @@ -1946,10 +1921,7 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old, rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel, gfp); - if (rc != 0) - return rc; - - return 0; + return rc; } /** @@ -4581,6 +4553,10 @@ static int smack_dentry_create_files_as(struct dentry *dentry, int mode, return 0; } +struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct task_smack), +}; + 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), @@ -4758,20 +4734,25 @@ static __init void init_smack_known_list(void) */ static __init int smack_init(void) { - struct cred *cred; + struct cred *cred = (struct cred *) current->cred; struct task_smack *tsp; smack_inode_cache = KMEM_CACHE(inode_smack, 0); if (!smack_inode_cache) return -ENOMEM; - tsp = new_task_smack(&smack_known_floor, &smack_known_floor, - GFP_KERNEL); - if (tsp == NULL) { - kmem_cache_destroy(smack_inode_cache); - return -ENOMEM; - } + lsm_early_cred(cred); + /* + * Set the security state for the initial task. + */ + tsp = smack_cred(cred); + init_task_smack(tsp, &smack_known_floor, &smack_known_floor); + + /* + * Register with LSM + */ + security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); smack_enabled = 1; pr_info("Smack: Initializing.\n"); @@ -4785,20 +4766,9 @@ static __init int smack_init(void) pr_info("Smack: IPv6 Netfilter enabled.\n"); #endif - /* - * Set the security state for the initial task. - */ - cred = (struct cred *) current->cred; - cred->security = tsp; - /* initialize the smack_known_list */ init_smack_known_list(); - /* - * Register with LSM - */ - security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack"); - return 0; } @@ -4809,5 +4779,6 @@ static __init int smack_init(void) DEFINE_LSM(smack) = { .name = "smack", .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, + .blobs = &smack_blob_sizes, .init = smack_init, }; diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h index 41898613d93b..4fc17294a12d 100644 --- a/security/tomoyo/common.h +++ b/security/tomoyo/common.h @@ -1087,6 +1087,7 @@ extern struct tomoyo_domain_info tomoyo_kernel_domain; extern struct tomoyo_policy_namespace tomoyo_kernel_namespace; extern unsigned int tomoyo_memory_quota[TOMOYO_MAX_MEMORY_STAT]; extern unsigned int tomoyo_memory_used[TOMOYO_MAX_MEMORY_STAT]; +extern struct lsm_blob_sizes tomoyo_blob_sizes; /********** Inlined functions. **********/ @@ -1206,7 +1207,7 @@ static inline void tomoyo_put_group(struct tomoyo_group *group) */ static inline struct tomoyo_domain_info **tomoyo_cred(const struct cred *cred) { - return (struct tomoyo_domain_info **)&cred->security; + return cred->security + tomoyo_blob_sizes.lbs_cred; } /** diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 15864307925d..9094cf41a247 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -509,6 +509,10 @@ static int tomoyo_socket_sendmsg(struct socket *sock, struct msghdr *msg, return tomoyo_socket_sendmsg_permission(sock, msg, size); } +struct lsm_blob_sizes tomoyo_blob_sizes __lsm_ro_after_init = { + .lbs_cred = sizeof(struct tomoyo_domain_info *), +}; + /* * tomoyo_security_ops is a "struct security_operations" which is used for * registering TOMOYO. @@ -562,6 +566,7 @@ static int __init tomoyo_init(void) /* register ourselves with the security framework */ security_add_hooks(tomoyo_hooks, ARRAY_SIZE(tomoyo_hooks), "tomoyo"); printk(KERN_INFO "TOMOYO Linux initialized\n"); + lsm_early_cred(cred); blob = tomoyo_cred(cred); *blob = &tomoyo_kernel_domain; tomoyo_mm_init(); @@ -573,5 +578,6 @@ DEFINE_LSM(tomoyo) = { .name = "tomoyo", .enabled = &tomoyo_enabled, .flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE, + .blobs = &tomoyo_blob_sizes, .init = tomoyo_init, };