* [PATCH v22 02/23] LSM: Create and manage the lsmblob data structure. [not found] <20201105004924.11651-1-casey@schaufler-ca.com> @ 2020-11-05 0:49 ` Casey Schaufler 0 siblings, 0 replies; 2+ messages in thread From: Casey Schaufler @ 2020-11-05 0:49 UTC (permalink / raw) To: casey.schaufler, jmorris, linux-security-module, selinux Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul, sds, linux-kernel, bpf 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. Because IMA uses the audit rule functions it is affected as well. Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Cc: <bpf@vger.kernel.org> --- include/linux/audit.h | 4 +- include/linux/lsm_hooks.h | 12 ++++- include/linux/security.h | 67 +++++++++++++++++++++++++-- kernel/auditfilter.c | 24 +++++----- kernel/auditsc.c | 12 ++--- security/apparmor/lsm.c | 7 ++- security/bpf/hooks.c | 12 ++++- security/commoncap.c | 7 ++- security/integrity/ima/ima_policy.c | 40 +++++++++++----- security/loadpin/loadpin.c | 8 +++- security/lockdown/lockdown.c | 7 ++- security/safesetid/lsm.c | 8 +++- security/security.c | 72 ++++++++++++++++++++++++----- security/selinux/hooks.c | 8 +++- security/smack/smack_lsm.c | 7 ++- security/tomoyo/tomoyo.c | 8 +++- security/yama/yama_lsm.c | 7 ++- 17 files changed, 254 insertions(+), 56 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index b3d859831a31..ba1cd38d601b 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 <uapi/linux/audit.h> #include <uapi/linux/netfilter/nf_tables.h> @@ -65,8 +66,9 @@ struct audit_field { kuid_t uid; kgid_t gid; struct { + bool lsm_isset; char *lsm_str; - void *lsm_rule; + void *lsm_rules[LSMBLOB_ENTRIES]; }; }; u32 op; diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index d8f492ed6ebf..fe9203f15993 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1545,6 +1545,14 @@ 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. @@ -1553,7 +1561,7 @@ 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; /* @@ -1588,7 +1596,7 @@ 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 bc2725491560..fdb6e95c98e8 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -132,6 +132,65 @@ 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 + * @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 = {}; + + 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) +{ + 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); @@ -1833,8 +1892,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_SECURITY int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule); 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, void **lsmrule); +void security_audit_rule_free(void **lsmrule); #else @@ -1850,12 +1909,12 @@ 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) + void **lsmrule) { return 0; } -static inline void security_audit_rule_free(void *lsmrule) +static inline void security_audit_rule_free(void **lsmrule) { } #endif /* CONFIG_SECURITY */ diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 333b3bcfc545..45da229f9f1f 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -74,7 +74,7 @@ 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); } } @@ -519,9 +519,10 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, goto exit_free; } entry->rule.buflen += f_val; + f->lsm_isset = true; 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) { @@ -774,7 +775,7 @@ 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) @@ -788,9 +789,9 @@ 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) { @@ -842,7 +843,7 @@ 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) { @@ -1358,10 +1359,11 @@ 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_isset) { security_task_getsecid(current, &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: @@ -1388,7 +1390,7 @@ 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; @@ -1420,7 +1422,7 @@ 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 @@ -1435,7 +1437,7 @@ 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 8dba8f0983b5..16e3430f7d07 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -667,14 +667,14 @@ 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_isset) { if (need_sid) { security_task_getsecid(tsk, &sid); need_sid = 0; } result = security_audit_rule_match(sid, f->type, f->op, - f->lsm_rule); + f->lsm_rules); } break; case AUDIT_OBJ_USER: @@ -684,21 +684,21 @@ 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_isset) { /* 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)) { + f->lsm_rules)) { ++result; break; } @@ -709,7 +709,7 @@ 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 f1c365905d5e..432915c1d427 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1152,6 +1152,11 @@ 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), @@ -1852,7 +1857,7 @@ 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 788667d582ae..a1a5032a4d87 100644 --- a/security/bpf/hooks.c +++ b/security/bpf/hooks.c @@ -14,9 +14,19 @@ static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(inode_free_security, bpf_inode_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 59bf3c1674c8..959a9f96b7f1 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1341,6 +1341,11 @@ 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), @@ -1365,7 +1370,7 @@ 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/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 9b5adeaa47fc..cd393aaa17d5 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -79,7 +79,7 @@ struct ima_rule_entry { bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */ int pcr; struct { - void *rule; /* LSM file metadata specific */ + void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */ char *args_p; /* audit value */ int type; /* audit type */ } lsm[MAX_LSM_RULES]; @@ -88,6 +88,22 @@ struct ima_rule_entry { struct ima_template_desc *template; }; +/** + * ima_lsm_isset - Is a rule set for any of the active security modules + * @rules: The set of IMA rules to check. + * + * If a rule is set for any LSM return true, otherwise return false. + */ +static inline bool ima_lsm_isset(void *rules[]) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + if (rules[i]) + return true; + return false; +} + /* * Without LSM specific knowledge, the default policy can only be * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner @@ -326,9 +342,11 @@ static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list) static void ima_lsm_free_rule(struct ima_rule_entry *entry) { int i; + int r; for (i = 0; i < MAX_LSM_RULES; i++) { - ima_filter_rule_free(entry->lsm[i].rule); + for (r = 0; r < LSMBLOB_ENTRIES; r++) + ima_filter_rule_free(entry->lsm[i].rules[r]); kfree(entry->lsm[i].args_p); } } @@ -379,8 +397,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) ima_filter_rule_init(nentry->lsm[i].type, Audit_equal, nentry->lsm[i].args_p, - &nentry->lsm[i].rule); - if (!nentry->lsm[i].rule) + &nentry->lsm[i].rules[0]); + if (!ima_lsm_isset(nentry->lsm[i].rules)) pr_warn("rule for LSM \'%s\' is undefined\n", nentry->lsm[i].args_p); } @@ -545,7 +563,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, int rc = 0; u32 osid; - if (!rule->lsm[i].rule) { + if (!ima_lsm_isset(rule->lsm[i].rules)) { if (!rule->lsm[i].args_p) continue; else @@ -558,14 +576,14 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, security_inode_getsecid(inode, &osid); rc = ima_filter_rule_match(osid, rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + rule->lsm[i].rules); break; case LSM_SUBJ_USER: case LSM_SUBJ_ROLE: case LSM_SUBJ_TYPE: rc = ima_filter_rule_match(secid, rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + rule->lsm[i].rules); default: break; } @@ -952,7 +970,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, { int result; - if (entry->lsm[lsm_rule].rule) + if (ima_lsm_isset(entry->lsm[lsm_rule].rules)) return -EINVAL; entry->lsm[lsm_rule].args_p = match_strdup(args); @@ -962,8 +980,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, entry->lsm[lsm_rule].type = audit_type; result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal, entry->lsm[lsm_rule].args_p, - &entry->lsm[lsm_rule].rule); - if (!entry->lsm[lsm_rule].rule) { + &entry->lsm[lsm_rule].rules[0]); + if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) { pr_warn("rule for LSM \'%s\' is undefined\n", entry->lsm[lsm_rule].args_p); @@ -1733,7 +1751,7 @@ int ima_policy_show(struct seq_file *m, void *v) } for (i = 0; i < MAX_LSM_RULES; i++) { - if (entry->lsm[i].rule) { + if (ima_lsm_isset(entry->lsm[i].rules)) { switch (i) { case LSM_OBJ_USER: seq_printf(m, pt(Opt_obj_user), 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 8a176b6adbe5..7c7ac9bfe5cd 100644 --- a/security/safesetid/lsm.c +++ b/security/safesetid/lsm.c @@ -244,6 +244,11 @@ 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), @@ -253,7 +258,8 @@ 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 5da8b3643680..d01363cb0082 100644 --- a/security/security.c +++ b/security/security.c @@ -341,6 +341,7 @@ static void __init ordered_lsm_init(void) init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); 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 @@ -468,21 +469,36 @@ 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 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; + 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); } @@ -491,7 +507,7 @@ 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__); } } @@ -2005,7 +2021,7 @@ 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); } @@ -2018,7 +2034,7 @@ 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); } @@ -2510,7 +2526,24 @@ int security_key_getsecurity(struct key *key, char **_buffer) int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) { - 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, + &lsmrule[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) @@ -2518,14 +2551,31 @@ 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(void **lsmrule) { - 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; + hp->hook.audit_rule_free(lsmrule[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, void **lsmrule) { - 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; + rc = hp->hook.audit_rule_match(secid, field, op, + &lsmrule[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 2748281a5cca..52a50d7ca534 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6933,6 +6933,11 @@ static int selinux_perf_event_write(struct perf_event *event) } #endif +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, @@ -7244,7 +7249,8 @@ 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 ca4a6c862732..f96be93d1a75 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4693,6 +4693,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { .lbs_sock = sizeof(struct socket_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), @@ -4892,7 +4897,7 @@ 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 1f3cd432d830..22f62c67f2ec 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -523,6 +523,11 @@ 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. @@ -575,7 +580,8 @@ 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; } -- 2.24.1 ^ permalink raw reply related [flat|nested] 2+ messages in thread
[parent not found: <20201104234114.11346-1-casey@schaufler-ca.com>]
* [PATCH v22 02/23] LSM: Create and manage the lsmblob data structure. [not found] <20201104234114.11346-1-casey@schaufler-ca.com> @ 2020-11-04 23:40 ` Casey Schaufler 0 siblings, 0 replies; 2+ messages in thread From: Casey Schaufler @ 2020-11-04 23:40 UTC (permalink / raw) To: casey.schaufler, jmorris, linux-security-module, selinux Cc: casey, linux-audit, keescook, john.johansen, penguin-kernel, paul, sds, linux-kernel, bpf 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. Because IMA uses the audit rule functions it is affected as well. Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Cc: <bpf@vger.kernel.org> --- include/linux/audit.h | 4 +- include/linux/lsm_hooks.h | 12 ++++- include/linux/security.h | 67 +++++++++++++++++++++++++-- kernel/auditfilter.c | 24 +++++----- kernel/auditsc.c | 12 ++--- security/apparmor/lsm.c | 7 ++- security/bpf/hooks.c | 12 ++++- security/commoncap.c | 7 ++- security/integrity/ima/ima_policy.c | 40 +++++++++++----- security/loadpin/loadpin.c | 8 +++- security/lockdown/lockdown.c | 7 ++- security/safesetid/lsm.c | 8 +++- security/security.c | 72 ++++++++++++++++++++++++----- security/selinux/hooks.c | 8 +++- security/smack/smack_lsm.c | 7 ++- security/tomoyo/tomoyo.c | 8 +++- security/yama/yama_lsm.c | 7 ++- 17 files changed, 254 insertions(+), 56 deletions(-) diff --git a/include/linux/audit.h b/include/linux/audit.h index b3d859831a31..ba1cd38d601b 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 <uapi/linux/audit.h> #include <uapi/linux/netfilter/nf_tables.h> @@ -65,8 +66,9 @@ struct audit_field { kuid_t uid; kgid_t gid; struct { + bool lsm_isset; char *lsm_str; - void *lsm_rule; + void *lsm_rules[LSMBLOB_ENTRIES]; }; }; u32 op; diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index d8f492ed6ebf..fe9203f15993 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1545,6 +1545,14 @@ 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. @@ -1553,7 +1561,7 @@ 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; /* @@ -1588,7 +1596,7 @@ 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 bc2725491560..fdb6e95c98e8 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -132,6 +132,65 @@ 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 + * @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 = {}; + + 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) +{ + 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); @@ -1833,8 +1892,8 @@ static inline int security_key_getsecurity(struct key *key, char **_buffer) #ifdef CONFIG_SECURITY int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule); 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, void **lsmrule); +void security_audit_rule_free(void **lsmrule); #else @@ -1850,12 +1909,12 @@ 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) + void **lsmrule) { return 0; } -static inline void security_audit_rule_free(void *lsmrule) +static inline void security_audit_rule_free(void **lsmrule) { } #endif /* CONFIG_SECURITY */ diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 333b3bcfc545..45da229f9f1f 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -74,7 +74,7 @@ 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); } } @@ -519,9 +519,10 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, goto exit_free; } entry->rule.buflen += f_val; + f->lsm_isset = true; 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) { @@ -774,7 +775,7 @@ 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) @@ -788,9 +789,9 @@ 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) { @@ -842,7 +843,7 @@ 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) { @@ -1358,10 +1359,11 @@ 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_isset) { security_task_getsecid(current, &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: @@ -1388,7 +1390,7 @@ 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; @@ -1420,7 +1422,7 @@ 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 @@ -1435,7 +1437,7 @@ 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 8dba8f0983b5..16e3430f7d07 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -667,14 +667,14 @@ 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_isset) { if (need_sid) { security_task_getsecid(tsk, &sid); need_sid = 0; } result = security_audit_rule_match(sid, f->type, f->op, - f->lsm_rule); + f->lsm_rules); } break; case AUDIT_OBJ_USER: @@ -684,21 +684,21 @@ 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_isset) { /* 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)) { + f->lsm_rules)) { ++result; break; } @@ -709,7 +709,7 @@ 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 f1c365905d5e..432915c1d427 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -1152,6 +1152,11 @@ 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), @@ -1852,7 +1857,7 @@ 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 788667d582ae..a1a5032a4d87 100644 --- a/security/bpf/hooks.c +++ b/security/bpf/hooks.c @@ -14,9 +14,19 @@ static struct security_hook_list bpf_lsm_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(inode_free_security, bpf_inode_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 59bf3c1674c8..959a9f96b7f1 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1341,6 +1341,11 @@ 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), @@ -1365,7 +1370,7 @@ 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/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 9b5adeaa47fc..cd393aaa17d5 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -79,7 +79,7 @@ struct ima_rule_entry { bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */ int pcr; struct { - void *rule; /* LSM file metadata specific */ + void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */ char *args_p; /* audit value */ int type; /* audit type */ } lsm[MAX_LSM_RULES]; @@ -88,6 +88,22 @@ struct ima_rule_entry { struct ima_template_desc *template; }; +/** + * ima_lsm_isset - Is a rule set for any of the active security modules + * @rules: The set of IMA rules to check. + * + * If a rule is set for any LSM return true, otherwise return false. + */ +static inline bool ima_lsm_isset(void *rules[]) +{ + int i; + + for (i = 0; i < LSMBLOB_ENTRIES; i++) + if (rules[i]) + return true; + return false; +} + /* * Without LSM specific knowledge, the default policy can only be * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner @@ -326,9 +342,11 @@ static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list) static void ima_lsm_free_rule(struct ima_rule_entry *entry) { int i; + int r; for (i = 0; i < MAX_LSM_RULES; i++) { - ima_filter_rule_free(entry->lsm[i].rule); + for (r = 0; r < LSMBLOB_ENTRIES; r++) + ima_filter_rule_free(entry->lsm[i].rules[r]); kfree(entry->lsm[i].args_p); } } @@ -379,8 +397,8 @@ static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry) ima_filter_rule_init(nentry->lsm[i].type, Audit_equal, nentry->lsm[i].args_p, - &nentry->lsm[i].rule); - if (!nentry->lsm[i].rule) + &nentry->lsm[i].rules[0]); + if (!ima_lsm_isset(nentry->lsm[i].rules)) pr_warn("rule for LSM \'%s\' is undefined\n", nentry->lsm[i].args_p); } @@ -545,7 +563,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, int rc = 0; u32 osid; - if (!rule->lsm[i].rule) { + if (!ima_lsm_isset(rule->lsm[i].rules)) { if (!rule->lsm[i].args_p) continue; else @@ -558,14 +576,14 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, security_inode_getsecid(inode, &osid); rc = ima_filter_rule_match(osid, rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + rule->lsm[i].rules); break; case LSM_SUBJ_USER: case LSM_SUBJ_ROLE: case LSM_SUBJ_TYPE: rc = ima_filter_rule_match(secid, rule->lsm[i].type, Audit_equal, - rule->lsm[i].rule); + rule->lsm[i].rules); default: break; } @@ -952,7 +970,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, { int result; - if (entry->lsm[lsm_rule].rule) + if (ima_lsm_isset(entry->lsm[lsm_rule].rules)) return -EINVAL; entry->lsm[lsm_rule].args_p = match_strdup(args); @@ -962,8 +980,8 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, entry->lsm[lsm_rule].type = audit_type; result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal, entry->lsm[lsm_rule].args_p, - &entry->lsm[lsm_rule].rule); - if (!entry->lsm[lsm_rule].rule) { + &entry->lsm[lsm_rule].rules[0]); + if (!ima_lsm_isset(entry->lsm[lsm_rule].rules)) { pr_warn("rule for LSM \'%s\' is undefined\n", entry->lsm[lsm_rule].args_p); @@ -1733,7 +1751,7 @@ int ima_policy_show(struct seq_file *m, void *v) } for (i = 0; i < MAX_LSM_RULES; i++) { - if (entry->lsm[i].rule) { + if (ima_lsm_isset(entry->lsm[i].rules)) { switch (i) { case LSM_OBJ_USER: seq_printf(m, pt(Opt_obj_user), 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 8a176b6adbe5..7c7ac9bfe5cd 100644 --- a/security/safesetid/lsm.c +++ b/security/safesetid/lsm.c @@ -244,6 +244,11 @@ 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), @@ -253,7 +258,8 @@ 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 5da8b3643680..d01363cb0082 100644 --- a/security/security.c +++ b/security/security.c @@ -341,6 +341,7 @@ static void __init ordered_lsm_init(void) init_debug("msg_msg blob size = %d\n", blob_sizes.lbs_msg_msg); init_debug("sock blob size = %d\n", blob_sizes.lbs_sock); 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 @@ -468,21 +469,36 @@ 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 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; + 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); } @@ -491,7 +507,7 @@ 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__); } } @@ -2005,7 +2021,7 @@ 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); } @@ -2018,7 +2034,7 @@ 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); } @@ -2510,7 +2526,24 @@ int security_key_getsecurity(struct key *key, char **_buffer) int security_audit_rule_init(u32 field, u32 op, char *rulestr, void **lsmrule) { - 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, + &lsmrule[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) @@ -2518,14 +2551,31 @@ 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(void **lsmrule) { - 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; + hp->hook.audit_rule_free(lsmrule[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, void **lsmrule) { - 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; + rc = hp->hook.audit_rule_match(secid, field, op, + &lsmrule[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 2748281a5cca..52a50d7ca534 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6933,6 +6933,11 @@ static int selinux_perf_event_write(struct perf_event *event) } #endif +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, @@ -7244,7 +7249,8 @@ 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 ca4a6c862732..f96be93d1a75 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4693,6 +4693,11 @@ struct lsm_blob_sizes smack_blob_sizes __lsm_ro_after_init = { .lbs_sock = sizeof(struct socket_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), @@ -4892,7 +4897,7 @@ 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 1f3cd432d830..22f62c67f2ec 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -523,6 +523,11 @@ 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. @@ -575,7 +580,8 @@ 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; } -- 2.24.1 ^ permalink raw reply related [flat|nested] 2+ messages in thread
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[not found] <20201105004924.11651-1-casey@schaufler-ca.com>
2020-11-05 0:49 ` [PATCH v22 02/23] LSM: Create and manage the lsmblob data structure Casey Schaufler
[not found] <20201104234114.11346-1-casey@schaufler-ca.com>
2020-11-04 23:40 ` Casey Schaufler
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