/* * Implementation of the security services. * * Authors : Stephen Smalley, * James Morris * * Updated: Trusted Computer Solutions, Inc. * * Support for enhanced MLS infrastructure. * Support for context based audit filters. * * Updated: Frank Mayer and Karl MacMillan * * Added conditional policy language extensions * * Updated: Hewlett-Packard * * Added support for NetLabel * Added support for the policy capability bitmap * * Updated: Chad Sellers * * Added validation of kernel classes and permissions * * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P. * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC * Copyright (C) 2003 Red Hat, Inc., James Morris * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, version 2. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "flask.h" #include "avc.h" #include "avc_ss.h" #include "security.h" #include "context.h" #include "policydb.h" #include "sidtab.h" #include "services.h" #include "conditional.h" #include "mls.h" #include "objsec.h" #include "netlabel.h" #include "xfrm.h" #include "ebitmap.h" #include "audit.h" extern void selnl_notify_policyload(u32 seqno); unsigned int policydb_loaded_version; int selinux_policycap_netpeer; int selinux_policycap_openperm; /* * This is declared in avc.c */ extern const struct selinux_class_perm selinux_class_perm; static DEFINE_RWLOCK(policy_rwlock); static DEFINE_MUTEX(load_mutex); static struct sidtab sidtab; struct policydb policydb; int ss_initialized; /* * The largest sequence number that has been used when * providing an access decision to the access vector cache. * The sequence number only changes when a policy change * occurs. */ static u32 latest_granting; /* Forward declaration. */ static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len); /* * Return the boolean value of a constraint expression * when it is applied to the specified source and target * security contexts. * * xcontext is a special beast... It is used by the validatetrans rules * only. For these rules, scontext is the context before the transition, * tcontext is the context after the transition, and xcontext is the context * of the process performing the transition. All other callers of * constraint_expr_eval should pass in NULL for xcontext. */ static int constraint_expr_eval(struct context *scontext, struct context *tcontext, struct context *xcontext, struct constraint_expr *cexpr) { u32 val1, val2; struct context *c; struct role_datum *r1, *r2; struct mls_level *l1, *l2; struct constraint_expr *e; int s[CEXPR_MAXDEPTH]; int sp = -1; for (e = cexpr; e; e = e->next) { switch (e->expr_type) { case CEXPR_NOT: BUG_ON(sp < 0); s[sp] = !s[sp]; break; case CEXPR_AND: BUG_ON(sp < 1); sp--; s[sp] &= s[sp+1]; break; case CEXPR_OR: BUG_ON(sp < 1); sp--; s[sp] |= s[sp+1]; break; case CEXPR_ATTR: if (sp == (CEXPR_MAXDEPTH-1)) return 0; switch (e->attr) { case CEXPR_USER: val1 = scontext->user; val2 = tcontext->user; break; case CEXPR_TYPE: val1 = scontext->type; val2 = tcontext->type; break; case CEXPR_ROLE: val1 = scontext->role; val2 = tcontext->role; r1 = policydb.role_val_to_struct[val1 - 1]; r2 = policydb.role_val_to_struct[val2 - 1]; switch (e->op) { case CEXPR_DOM: s[++sp] = ebitmap_get_bit(&r1->dominates, val2 - 1); continue; case CEXPR_DOMBY: s[++sp] = ebitmap_get_bit(&r2->dominates, val1 - 1); continue; case CEXPR_INCOMP: s[++sp] = (!ebitmap_get_bit(&r1->dominates, val2 - 1) && !ebitmap_get_bit(&r2->dominates, val1 - 1)); continue; default: break; } break; case CEXPR_L1L2: l1 = &(scontext->range.level[0]); l2 = &(tcontext->range.level[0]); goto mls_ops; case CEXPR_L1H2: l1 = &(scontext->range.level[0]); l2 = &(tcontext->range.level[1]); goto mls_ops; case CEXPR_H1L2: l1 = &(scontext->range.level[1]); l2 = &(tcontext->range.level[0]); goto mls_ops; case CEXPR_H1H2: l1 = &(scontext->range.level[1]); l2 = &(tcontext->range.level[1]); goto mls_ops; case CEXPR_L1H1: l1 = &(scontext->range.level[0]); l2 = &(scontext->range.level[1]); goto mls_ops; case CEXPR_L2H2: l1 = &(tcontext->range.level[0]); l2 = &(tcontext->range.level[1]); goto mls_ops; mls_ops: switch (e->op) { case CEXPR_EQ: s[++sp] = mls_level_eq(l1, l2); continue; case CEXPR_NEQ: s[++sp] = !mls_level_eq(l1, l2); continue; case CEXPR_DOM: s[++sp] = mls_level_dom(l1, l2); continue; case CEXPR_DOMBY: s[++sp] = mls_level_dom(l2, l1); continue; case CEXPR_INCOMP: s[++sp] = mls_level_incomp(l2, l1); continue; default: BUG(); return 0; } break; default: BUG(); return 0; } switch (e->op) { case CEXPR_EQ: s[++sp] = (val1 == val2); break; case CEXPR_NEQ: s[++sp] = (val1 != val2); break; default: BUG(); return 0; } break; case CEXPR_NAMES: if (sp == (CEXPR_MAXDEPTH-1)) return 0; c = scontext; if (e->attr & CEXPR_TARGET) c = tcontext; else if (e->attr & CEXPR_XTARGET) { c = xcontext; if (!c) { BUG(); return 0; } } if (e->attr & CEXPR_USER) val1 = c->user; else if (e->attr & CEXPR_ROLE) val1 = c->role; else if (e->attr & CEXPR_TYPE) val1 = c->type; else { BUG(); return 0; } switch (e->op) { case CEXPR_EQ: s[++sp] = ebitmap_get_bit(&e->names, val1 - 1); break; case CEXPR_NEQ: s[++sp] = !ebitmap_get_bit(&e->names, val1 - 1); break; default: BUG(); return 0; } break; default: BUG(); return 0; } } BUG_ON(sp != 0); return s[0]; } /* * Compute access vectors based on a context structure pair for * the permissions in a particular class. */ static int context_struct_compute_av(struct context *scontext, struct context *tcontext, u16 tclass, u32 requested, struct av_decision *avd) { struct constraint_node *constraint; struct role_allow *ra; struct avtab_key avkey; struct avtab_node *node; struct class_datum *tclass_datum; struct ebitmap *sattr, *tattr; struct ebitmap_node *snode, *tnode; const struct selinux_class_perm *kdefs = &selinux_class_perm; unsigned int i, j; /* * Remap extended Netlink classes for old policy versions. * Do this here rather than socket_type_to_security_class() * in case a newer policy version is loaded, allowing sockets * to remain in the correct class. */ if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && tclass <= SECCLASS_NETLINK_DNRT_SOCKET) tclass = SECCLASS_NETLINK_SOCKET; /* * Initialize the access vectors to the default values. */ avd->allowed = 0; avd->decided = 0xffffffff; avd->auditallow = 0; avd->auditdeny = 0xffffffff; avd->seqno = latest_granting; /* * Check for all the invalid cases. * - tclass 0 * - tclass > policy and > kernel * - tclass > policy but is a userspace class * - tclass > policy but we do not allow unknowns */ if (unlikely(!tclass)) goto inval_class; if (unlikely(tclass > policydb.p_classes.nprim)) if (tclass > kdefs->cts_len || !kdefs->class_to_string[tclass] || !policydb.allow_unknown) goto inval_class; /* * Kernel class and we allow unknown so pad the allow decision * the pad will be all 1 for unknown classes. */ if (tclass <= kdefs->cts_len && policydb.allow_unknown) avd->allowed = policydb.undefined_perms[tclass - 1]; /* * Not in policy. Since decision is completed (all 1 or all 0) return. */ if (unlikely(tclass > policydb.p_classes.nprim)) return 0; tclass_datum = policydb.class_val_to_struct[tclass - 1]; /* * If a specific type enforcement rule was defined for * this permission check, then use it. */ avkey.target_class = tclass; avkey.specified = AVTAB_AV; sattr = &policydb.type_attr_map[scontext->type - 1]; tattr = &policydb.type_attr_map[tcontext->type - 1]; ebitmap_for_each_positive_bit(sattr, snode, i) { ebitmap_for_each_positive_bit(tattr, tnode, j) { avkey.source_type = i + 1; avkey.target_type = j + 1; for (node = avtab_search_node(&policydb.te_avtab, &avkey); node != NULL; node = avtab_search_node_next(node, avkey.specified)) { if (node->key.specified == AVTAB_ALLOWED) avd->allowed |= node->datum.data; else if (node->key.specified == AVTAB_AUDITALLOW) avd->auditallow |= node->datum.data; else if (node->key.specified == AVTAB_AUDITDENY) avd->auditdeny &= node->datum.data; } /* Check conditional av table for additional permissions */ cond_compute_av(&policydb.te_cond_avtab, &avkey, avd); } } /* * Remove any permissions prohibited by a constraint (this includes * the MLS policy). */ constraint = tclass_datum->constraints; while (constraint) { if ((constraint->permissions & (avd->allowed)) && !constraint_expr_eval(scontext, tcontext, NULL, constraint->expr)) { avd->allowed = (avd->allowed) & ~(constraint->permissions); } constraint = constraint->next; } /* * If checking process transition permission and the * role is changing, then check the (current_role, new_role) * pair. */ if (tclass == SECCLASS_PROCESS && (avd->allowed & (PROCESS__TRANSITION | PROCESS__DYNTRANSITION)) && scontext->role != tcontext->role) { for (ra = policydb.role_allow; ra; ra = ra->next) { if (scontext->role == ra->role && tcontext->role == ra->new_role) break; } if (!ra) avd->allowed = (avd->allowed) & ~(PROCESS__TRANSITION | PROCESS__DYNTRANSITION); } return 0; inval_class: printk(KERN_ERR "SELinux: %s: unrecognized class %d\n", __func__, tclass); return -EINVAL; } /* * Given a sid find if the type has the permissive flag set */ int security_permissive_sid(u32 sid) { struct context *context; u32 type; int rc; read_lock(&policy_rwlock); context = sidtab_search(&sidtab, sid); BUG_ON(!context); type = context->type; /* * we are intentionally using type here, not type-1, the 0th bit may * someday indicate that we are globally setting permissive in policy. */ rc = ebitmap_get_bit(&policydb.permissive_map, type); read_unlock(&policy_rwlock); return rc; } static int security_validtrans_handle_fail(struct context *ocontext, struct context *ncontext, struct context *tcontext, u16 tclass) { char *o = NULL, *n = NULL, *t = NULL; u32 olen, nlen, tlen; if (context_struct_to_string(ocontext, &o, &olen) < 0) goto out; if (context_struct_to_string(ncontext, &n, &nlen) < 0) goto out; if (context_struct_to_string(tcontext, &t, &tlen) < 0) goto out; audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, "security_validate_transition: denied for" " oldcontext=%s newcontext=%s taskcontext=%s tclass=%s", o, n, t, policydb.p_class_val_to_name[tclass-1]); out: kfree(o); kfree(n); kfree(t); if (!selinux_enforcing) return 0; return -EPERM; } int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid, u16 tclass) { struct context *ocontext; struct context *ncontext; struct context *tcontext; struct class_datum *tclass_datum; struct constraint_node *constraint; int rc = 0; if (!ss_initialized) return 0; read_lock(&policy_rwlock); /* * Remap extended Netlink classes for old policy versions. * Do this here rather than socket_type_to_security_class() * in case a newer policy version is loaded, allowing sockets * to remain in the correct class. */ if (policydb_loaded_version < POLICYDB_VERSION_NLCLASS) if (tclass >= SECCLASS_NETLINK_ROUTE_SOCKET && tclass <= SECCLASS_NETLINK_DNRT_SOCKET) tclass = SECCLASS_NETLINK_SOCKET; if (!tclass || tclass > policydb.p_classes.nprim) { printk(KERN_ERR "SELinux: %s: unrecognized class %d\n", __func__, tclass); rc = -EINVAL; goto out; } tclass_datum = policydb.class_val_to_struct[tclass - 1]; ocontext = sidtab_search(&sidtab, oldsid); if (!ocontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, oldsid); rc = -EINVAL; goto out; } ncontext = sidtab_search(&sidtab, newsid); if (!ncontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, newsid); rc = -EINVAL; goto out; } tcontext = sidtab_search(&sidtab, tasksid); if (!tcontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, tasksid); rc = -EINVAL; goto out; } constraint = tclass_datum->validatetrans; while (constraint) { if (!constraint_expr_eval(ocontext, ncontext, tcontext, constraint->expr)) { rc = security_validtrans_handle_fail(ocontext, ncontext, tcontext, tclass); goto out; } constraint = constraint->next; } out: read_unlock(&policy_rwlock); return rc; } /** * security_compute_av - Compute access vector decisions. * @ssid: source security identifier * @tsid: target security identifier * @tclass: target security class * @requested: requested permissions * @avd: access vector decisions * * Compute a set of access vector decisions based on the * SID pair (@ssid, @tsid) for the permissions in @tclass. * Return -%EINVAL if any of the parameters are invalid or %0 * if the access vector decisions were computed successfully. */ int security_compute_av(u32 ssid, u32 tsid, u16 tclass, u32 requested, struct av_decision *avd) { struct context *scontext = NULL, *tcontext = NULL; int rc = 0; if (!ss_initialized) { avd->allowed = 0xffffffff; avd->decided = 0xffffffff; avd->auditallow = 0; avd->auditdeny = 0xffffffff; avd->seqno = latest_granting; return 0; } read_lock(&policy_rwlock); scontext = sidtab_search(&sidtab, ssid); if (!scontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, ssid); rc = -EINVAL; goto out; } tcontext = sidtab_search(&sidtab, tsid); if (!tcontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, tsid); rc = -EINVAL; goto out; } rc = context_struct_compute_av(scontext, tcontext, tclass, requested, avd); out: read_unlock(&policy_rwlock); return rc; } /* * Write the security context string representation of * the context structure `context' into a dynamically * allocated string of the correct size. Set `*scontext' * to point to this string and set `*scontext_len' to * the length of the string. */ static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len) { char *scontextp; *scontext = NULL; *scontext_len = 0; if (context->len) { *scontext_len = context->len; *scontext = kstrdup(context->str, GFP_ATOMIC); if (!(*scontext)) return -ENOMEM; return 0; } /* Compute the size of the context. */ *scontext_len += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1; *scontext_len += strlen(policydb.p_role_val_to_name[context->role - 1]) + 1; *scontext_len += strlen(policydb.p_type_val_to_name[context->type - 1]) + 1; *scontext_len += mls_compute_context_len(context); /* Allocate space for the context; caller must free this space. */ scontextp = kmalloc(*scontext_len, GFP_ATOMIC); if (!scontextp) return -ENOMEM; *scontext = scontextp; /* * Copy the user name, role name and type name into the context. */ sprintf(scontextp, "%s:%s:%s", policydb.p_user_val_to_name[context->user - 1], policydb.p_role_val_to_name[context->role - 1], policydb.p_type_val_to_name[context->type - 1]); scontextp += strlen(policydb.p_user_val_to_name[context->user - 1]) + 1 + strlen(policydb.p_role_val_to_name[context->role - 1]) + 1 + strlen(policydb.p_type_val_to_name[context->type - 1]); mls_sid_to_context(context, &scontextp); *scontextp = 0; return 0; } #include "initial_sid_to_string.h" const char *security_get_initial_sid_context(u32 sid) { if (unlikely(sid > SECINITSID_NUM)) return NULL; return initial_sid_to_string[sid]; } static int security_sid_to_context_core(u32 sid, char **scontext, u32 *scontext_len, int force) { struct context *context; int rc = 0; *scontext = NULL; *scontext_len = 0; if (!ss_initialized) { if (sid <= SECINITSID_NUM) { char *scontextp; *scontext_len = strlen(initial_sid_to_string[sid]) + 1; scontextp = kmalloc(*scontext_len, GFP_ATOMIC); if (!scontextp) { rc = -ENOMEM; goto out; } strcpy(scontextp, initial_sid_to_string[sid]); *scontext = scontextp; goto out; } printk(KERN_ERR "SELinux: %s: called before initial " "load_policy on unknown SID %d\n", __func__, sid); rc = -EINVAL; goto out; } read_lock(&policy_rwlock); if (force) context = sidtab_search_force(&sidtab, sid); else context = sidtab_search(&sidtab, sid); if (!context) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, sid); rc = -EINVAL; goto out_unlock; } rc = context_struct_to_string(context, scontext, scontext_len); out_unlock: read_unlock(&policy_rwlock); out: return rc; } /** * security_sid_to_context - Obtain a context for a given SID. * @sid: security identifier, SID * @scontext: security context * @scontext_len: length in bytes * * Write the string representation of the context associated with @sid * into a dynamically allocated string of the correct size. Set @scontext * to point to this string and set @scontext_len to the length of the string. */ int security_sid_to_context(u32 sid, char **scontext, u32 *scontext_len) { return security_sid_to_context_core(sid, scontext, scontext_len, 0); } int security_sid_to_context_force(u32 sid, char **scontext, u32 *scontext_len) { return security_sid_to_context_core(sid, scontext, scontext_len, 1); } /* * Caveat: Mutates scontext. */ static int string_to_context_struct(struct policydb *pol, struct sidtab *sidtabp, char *scontext, u32 scontext_len, struct context *ctx, u32 def_sid) { struct role_datum *role; struct type_datum *typdatum; struct user_datum *usrdatum; char *scontextp, *p, oldc; int rc = 0; context_init(ctx); /* Parse the security context. */ rc = -EINVAL; scontextp = (char *) scontext; /* Extract the user. */ p = scontextp; while (*p && *p != ':') p++; if (*p == 0) goto out; *p++ = 0; usrdatum = hashtab_search(pol->p_users.table, scontextp); if (!usrdatum) goto out; ctx->user = usrdatum->value; /* Extract role. */ scontextp = p; while (*p && *p != ':') p++; if (*p == 0) goto out; *p++ = 0; role = hashtab_search(pol->p_roles.table, scontextp); if (!role) goto out; ctx->role = role->value; /* Extract type. */ scontextp = p; while (*p && *p != ':') p++; oldc = *p; *p++ = 0; typdatum = hashtab_search(pol->p_types.table, scontextp); if (!typdatum) goto out; ctx->type = typdatum->value; rc = mls_context_to_sid(pol, oldc, &p, ctx, sidtabp, def_sid); if (rc) goto out; if ((p - scontext) < scontext_len) { rc = -EINVAL; goto out; } /* Check the validity of the new context. */ if (!policydb_context_isvalid(pol, ctx)) { rc = -EINVAL; context_destroy(ctx); goto out; } rc = 0; out: return rc; } static int security_context_to_sid_core(const char *scontext, u32 scontext_len, u32 *sid, u32 def_sid, gfp_t gfp_flags, int force) { char *scontext2, *str = NULL; struct context context; int rc = 0; if (!ss_initialized) { int i; for (i = 1; i < SECINITSID_NUM; i++) { if (!strcmp(initial_sid_to_string[i], scontext)) { *sid = i; return 0; } } *sid = SECINITSID_KERNEL; return 0; } *sid = SECSID_NULL; /* Copy the string so that we can modify the copy as we parse it. */ scontext2 = kmalloc(scontext_len+1, gfp_flags); if (!scontext2) return -ENOMEM; memcpy(scontext2, scontext, scontext_len); scontext2[scontext_len] = 0; if (force) { /* Save another copy for storing in uninterpreted form */ str = kstrdup(scontext2, gfp_flags); if (!str) { kfree(scontext2); return -ENOMEM; } } read_lock(&policy_rwlock); rc = string_to_context_struct(&policydb, &sidtab, scontext2, scontext_len, &context, def_sid); if (rc == -EINVAL && force) { context.str = str; context.len = scontext_len; str = NULL; } else if (rc) goto out; rc = sidtab_context_to_sid(&sidtab, &context, sid); if (rc) context_destroy(&context); out: read_unlock(&policy_rwlock); kfree(scontext2); kfree(str); return rc; } /** * security_context_to_sid - Obtain a SID for a given security context. * @scontext: security context * @scontext_len: length in bytes * @sid: security identifier, SID * * Obtains a SID associated with the security context that * has the string representation specified by @scontext. * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient * memory is available, or 0 on success. */ int security_context_to_sid(const char *scontext, u32 scontext_len, u32 *sid) { return security_context_to_sid_core(scontext, scontext_len, sid, SECSID_NULL, GFP_KERNEL, 0); } /** * security_context_to_sid_default - Obtain a SID for a given security context, * falling back to specified default if needed. * * @scontext: security context * @scontext_len: length in bytes * @sid: security identifier, SID * @def_sid: default SID to assign on error * * Obtains a SID associated with the security context that * has the string representation specified by @scontext. * The default SID is passed to the MLS layer to be used to allow * kernel labeling of the MLS field if the MLS field is not present * (for upgrading to MLS without full relabel). * Implicitly forces adding of the context even if it cannot be mapped yet. * Returns -%EINVAL if the context is invalid, -%ENOMEM if insufficient * memory is available, or 0 on success. */ int security_context_to_sid_default(const char *scontext, u32 scontext_len, u32 *sid, u32 def_sid, gfp_t gfp_flags) { return security_context_to_sid_core(scontext, scontext_len, sid, def_sid, gfp_flags, 1); } int security_context_to_sid_force(const char *scontext, u32 scontext_len, u32 *sid) { return security_context_to_sid_core(scontext, scontext_len, sid, SECSID_NULL, GFP_KERNEL, 1); } static int compute_sid_handle_invalid_context( struct context *scontext, struct context *tcontext, u16 tclass, struct context *newcontext) { char *s = NULL, *t = NULL, *n = NULL; u32 slen, tlen, nlen; if (context_struct_to_string(scontext, &s, &slen) < 0) goto out; if (context_struct_to_string(tcontext, &t, &tlen) < 0) goto out; if (context_struct_to_string(newcontext, &n, &nlen) < 0) goto out; audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, "security_compute_sid: invalid context %s" " for scontext=%s" " tcontext=%s" " tclass=%s", n, s, t, policydb.p_class_val_to_name[tclass-1]); out: kfree(s); kfree(t); kfree(n); if (!selinux_enforcing) return 0; return -EACCES; } static int security_compute_sid(u32 ssid, u32 tsid, u16 tclass, u32 specified, u32 *out_sid) { struct context *scontext = NULL, *tcontext = NULL, newcontext; struct role_trans *roletr = NULL; struct avtab_key avkey; struct avtab_datum *avdatum; struct avtab_node *node; int rc = 0; if (!ss_initialized) { switch (tclass) { case SECCLASS_PROCESS: *out_sid = ssid; break; default: *out_sid = tsid; break; } goto out; } context_init(&newcontext); read_lock(&policy_rwlock); scontext = sidtab_search(&sidtab, ssid); if (!scontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, ssid); rc = -EINVAL; goto out_unlock; } tcontext = sidtab_search(&sidtab, tsid); if (!tcontext) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, tsid); rc = -EINVAL; goto out_unlock; } /* Set the user identity. */ switch (specified) { case AVTAB_TRANSITION: case AVTAB_CHANGE: /* Use the process user identity. */ newcontext.user = scontext->user; break; case AVTAB_MEMBER: /* Use the related object owner. */ newcontext.user = tcontext->user; break; } /* Set the role and type to default values. */ switch (tclass) { case SECCLASS_PROCESS: /* Use the current role and type of process. */ newcontext.role = scontext->role; newcontext.type = scontext->type; break; default: /* Use the well-defined object role. */ newcontext.role = OBJECT_R_VAL; /* Use the type of the related object. */ newcontext.type = tcontext->type; } /* Look for a type transition/member/change rule. */ avkey.source_type = scontext->type; avkey.target_type = tcontext->type; avkey.target_class = tclass; avkey.specified = specified; avdatum = avtab_search(&policydb.te_avtab, &avkey); /* If no permanent rule, also check for enabled conditional rules */ if (!avdatum) { node = avtab_search_node(&policydb.te_cond_avtab, &avkey); for (; node != NULL; node = avtab_search_node_next(node, specified)) { if (node->key.specified & AVTAB_ENABLED) { avdatum = &node->datum; break; } } } if (avdatum) { /* Use the type from the type transition/member/change rule. */ newcontext.type = avdatum->data; } /* Check for class-specific changes. */ switch (tclass) { case SECCLASS_PROCESS: if (specified & AVTAB_TRANSITION) { /* Look for a role transition rule. */ for (roletr = policydb.role_tr; roletr; roletr = roletr->next) { if (roletr->role == scontext->role && roletr->type == tcontext->type) { /* Use the role transition rule. */ newcontext.role = roletr->new_role; break; } } } break; default: break; } /* Set the MLS attributes. This is done last because it may allocate memory. */ rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext); if (rc) goto out_unlock; /* Check the validity of the context. */ if (!policydb_context_isvalid(&policydb, &newcontext)) { rc = compute_sid_handle_invalid_context(scontext, tcontext, tclass, &newcontext); if (rc) goto out_unlock; } /* Obtain the sid for the context. */ rc = sidtab_context_to_sid(&sidtab, &newcontext, out_sid); out_unlock: read_unlock(&policy_rwlock); context_destroy(&newcontext); out: return rc; } /** * security_transition_sid - Compute the SID for a new subject/object. * @ssid: source security identifier * @tsid: target security identifier * @tclass: target security class * @out_sid: security identifier for new subject/object * * Compute a SID to use for labeling a new subject or object in the * class @tclass based on a SID pair (@ssid, @tsid). * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM * if insufficient memory is available, or %0 if the new SID was * computed successfully. */ int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, out_sid); } /** * security_member_sid - Compute the SID for member selection. * @ssid: source security identifier * @tsid: target security identifier * @tclass: target security class * @out_sid: security identifier for selected member * * Compute a SID to use when selecting a member of a polyinstantiated * object of class @tclass based on a SID pair (@ssid, @tsid). * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM * if insufficient memory is available, or %0 if the SID was * computed successfully. */ int security_member_sid(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid); } /** * security_change_sid - Compute the SID for object relabeling. * @ssid: source security identifier * @tsid: target security identifier * @tclass: target security class * @out_sid: security identifier for selected member * * Compute a SID to use for relabeling an object of class @tclass * based on a SID pair (@ssid, @tsid). * Return -%EINVAL if any of the parameters are invalid, -%ENOMEM * if insufficient memory is available, or %0 if the SID was * computed successfully. */ int security_change_sid(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid); } /* * Verify that each kernel class that is defined in the * policy is correct */ static int validate_classes(struct policydb *p) { int i, j; struct class_datum *cladatum; struct perm_datum *perdatum; u32 nprim, tmp, common_pts_len, perm_val, pol_val; u16 class_val; const struct selinux_class_perm *kdefs = &selinux_class_perm; const char *def_class, *def_perm, *pol_class; struct symtab *perms; if (p->allow_unknown) { u32 num_classes = kdefs->cts_len; p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL); if (!p->undefined_perms) return -ENOMEM; } for (i = 1; i < kdefs->cts_len; i++) { def_class = kdefs->class_to_string[i]; if (!def_class) continue; if (i > p->p_classes.nprim) { printk(KERN_INFO "SELinux: class %s not defined in policy\n", def_class); if (p->reject_unknown) return -EINVAL; if (p->allow_unknown) p->undefined_perms[i-1] = ~0U; continue; } pol_class = p->p_class_val_to_name[i-1]; if (strcmp(pol_class, def_class)) { printk(KERN_ERR "SELinux: class %d is incorrect, found %s but should be %s\n", i, pol_class, def_class); return -EINVAL; } } for (i = 0; i < kdefs->av_pts_len; i++) { class_val = kdefs->av_perm_to_string[i].tclass; perm_val = kdefs->av_perm_to_string[i].value; def_perm = kdefs->av_perm_to_string[i].name; if (class_val > p->p_classes.nprim) continue; pol_class = p->p_class_val_to_name[class_val-1]; cladatum = hashtab_search(p->p_classes.table, pol_class); BUG_ON(!cladatum); perms = &cladatum->permissions; nprim = 1 << (perms->nprim - 1); if (perm_val > nprim) { printk(KERN_INFO "SELinux: permission %s in class %s not defined in policy\n", def_perm, pol_class); if (p->reject_unknown) return -EINVAL; if (p->allow_unknown) p->undefined_perms[class_val-1] |= perm_val; continue; } perdatum = hashtab_search(perms->table, def_perm); if (perdatum == NULL) { printk(KERN_ERR "SELinux: permission %s in class %s not found in policy, bad policy\n", def_perm, pol_class); return -EINVAL; } pol_val = 1 << (perdatum->value - 1); if (pol_val != perm_val) { printk(KERN_ERR "SELinux: permission %s in class %s has incorrect value\n", def_perm, pol_class); return -EINVAL; } } for (i = 0; i < kdefs->av_inherit_len; i++) { class_val = kdefs->av_inherit[i].tclass; if (class_val > p->p_classes.nprim) continue; pol_class = p->p_class_val_to_name[class_val-1]; cladatum = hashtab_search(p->p_classes.table, pol_class); BUG_ON(!cladatum); if (!cladatum->comdatum) { printk(KERN_ERR "SELinux: class %s should have an inherits clause but does not\n", pol_class); return -EINVAL; } tmp = kdefs->av_inherit[i].common_base; common_pts_len = 0; while (!(tmp & 0x01)) { common_pts_len++; tmp >>= 1; } perms = &cladatum->comdatum->permissions; for (j = 0; j < common_pts_len; j++) { def_perm = kdefs->av_inherit[i].common_pts[j]; if (j >= perms->nprim) { printk(KERN_INFO "SELinux: permission %s in class %s not defined in policy\n", def_perm, pol_class); if (p->reject_unknown) return -EINVAL; if (p->allow_unknown) p->undefined_perms[class_val-1] |= (1 << j); continue; } perdatum = hashtab_search(perms->table, def_perm); if (perdatum == NULL) { printk(KERN_ERR "SELinux: permission %s in class %s not found in policy, bad policy\n", def_perm, pol_class); return -EINVAL; } if (perdatum->value != j + 1) { printk(KERN_ERR "SELinux: permission %s in class %s has incorrect value\n", def_perm, pol_class); return -EINVAL; } } } return 0; } /* Clone the SID into the new SID table. */ static int clone_sid(u32 sid, struct context *context, void *arg) { struct sidtab *s = arg; return sidtab_insert(s, sid, context); } static inline int convert_context_handle_invalid_context(struct context *context) { int rc = 0; if (selinux_enforcing) { rc = -EINVAL; } else { char *s; u32 len; if (!context_struct_to_string(context, &s, &len)) { printk(KERN_WARNING "SELinux: Context %s would be invalid if enforcing\n", s); kfree(s); } } return rc; } struct convert_context_args { struct policydb *oldp; struct policydb *newp; }; /* * Convert the values in the security context * structure `c' from the values specified * in the policy `p->oldp' to the values specified * in the policy `p->newp'. Verify that the * context is valid under the new policy. */ static int convert_context(u32 key, struct context *c, void *p) { struct convert_context_args *args; struct context oldc; struct role_datum *role; struct type_datum *typdatum; struct user_datum *usrdatum; char *s; u32 len; int rc; args = p; if (c->str) { struct context ctx; s = kstrdup(c->str, GFP_KERNEL); if (!s) { rc = -ENOMEM; goto out; } rc = string_to_context_struct(args->newp, NULL, s, c->len, &ctx, SECSID_NULL); kfree(s); if (!rc) { printk(KERN_INFO "SELinux: Context %s became valid (mapped).\n", c->str); /* Replace string with mapped representation. */ kfree(c->str); memcpy(c, &ctx, sizeof(*c)); goto out; } else if (rc == -EINVAL) { /* Retain string representation for later mapping. */ rc = 0; goto out; } else { /* Other error condition, e.g. ENOMEM. */ printk(KERN_ERR "SELinux: Unable to map context %s, rc = %d.\n", c->str, -rc); goto out; } } rc = context_cpy(&oldc, c); if (rc) goto out; rc = -EINVAL; /* Convert the user. */ usrdatum = hashtab_search(args->newp->p_users.table, args->oldp->p_user_val_to_name[c->user - 1]); if (!usrdatum) goto bad; c->user = usrdatum->value; /* Convert the role. */ role = hashtab_search(args->newp->p_roles.table, args->oldp->p_role_val_to_name[c->role - 1]); if (!role) goto bad; c->role = role->value; /* Convert the type. */ typdatum = hashtab_search(args->newp->p_types.table, args->oldp->p_type_val_to_name[c->type - 1]); if (!typdatum) goto bad; c->type = typdatum->value; rc = mls_convert_context(args->oldp, args->newp, c); if (rc) goto bad; /* Check the validity of the new context. */ if (!policydb_context_isvalid(args->newp, c)) { rc = convert_context_handle_invalid_context(&oldc); if (rc) goto bad; } context_destroy(&oldc); rc = 0; out: return rc; bad: /* Map old representation to string and save it. */ if (context_struct_to_string(&oldc, &s, &len)) return -ENOMEM; context_destroy(&oldc); context_destroy(c); c->str = s; c->len = len; printk(KERN_INFO "SELinux: Context %s became invalid (unmapped).\n", c->str); rc = 0; goto out; } static void security_load_policycaps(void) { selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps, POLICYDB_CAPABILITY_NETPEER); selinux_policycap_openperm = ebitmap_get_bit(&policydb.policycaps, POLICYDB_CAPABILITY_OPENPERM); } extern void selinux_complete_init(void); static int security_preserve_bools(struct policydb *p); /** * security_load_policy - Load a security policy configuration. * @data: binary policy data * @len: length of data in bytes * * Load a new set of security policy configuration data, * validate it and convert the SID table as necessary. * This function will flush the access vector cache after * loading the new policy. */ int security_load_policy(void *data, size_t len) { struct policydb oldpolicydb, newpolicydb; struct sidtab oldsidtab, newsidtab; struct convert_context_args args; u32 seqno; int rc = 0; struct policy_file file = { data, len }, *fp = &file; mutex_lock(&load_mutex); if (!ss_initialized) { avtab_cache_init(); if (policydb_read(&policydb, fp)) { mutex_unlock(&load_mutex); avtab_cache_destroy(); return -EINVAL; } if (policydb_load_isids(&policydb, &sidtab)) { mutex_unlock(&load_mutex); policydb_destroy(&policydb); avtab_cache_destroy(); return -EINVAL; } /* Verify that the kernel defined classes are correct. */ if (validate_classes(&policydb)) { printk(KERN_ERR "SELinux: the definition of a class is incorrect\n"); mutex_unlock(&load_mutex); sidtab_destroy(&sidtab); policydb_destroy(&policydb); avtab_cache_destroy(); return -EINVAL; } security_load_policycaps(); policydb_loaded_version = policydb.policyvers; ss_initialized = 1; seqno = ++latest_granting; mutex_unlock(&load_mutex); selinux_complete_init(); avc_ss_reset(seqno); selnl_notify_policyload(seqno); selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); return 0; } #if 0 sidtab_hash_eval(&sidtab, "sids"); #endif if (policydb_read(&newpolicydb, fp)) { mutex_unlock(&load_mutex); return -EINVAL; } if (sidtab_init(&newsidtab)) { mutex_unlock(&load_mutex); policydb_destroy(&newpolicydb); return -ENOMEM; } /* Verify that the kernel defined classes are correct. */ if (validate_classes(&newpolicydb)) { printk(KERN_ERR "SELinux: the definition of a class is incorrect\n"); rc = -EINVAL; goto err; } rc = security_preserve_bools(&newpolicydb); if (rc) { printk(KERN_ERR "SELinux: unable to preserve booleans\n"); goto err; } /* Clone the SID table. */ sidtab_shutdown(&sidtab); if (sidtab_map(&sidtab, clone_sid, &newsidtab)) { rc = -ENOMEM; goto err; } /* * Convert the internal representations of contexts * in the new SID table. */ args.oldp = &policydb; args.newp = &newpolicydb; rc = sidtab_map(&newsidtab, convert_context, &args); if (rc) goto err; /* Save the old policydb and SID table to free later. */ memcpy(&oldpolicydb, &policydb, sizeof policydb); sidtab_set(&oldsidtab, &sidtab); /* Install the new policydb and SID table. */ write_lock_irq(&policy_rwlock); memcpy(&policydb, &newpolicydb, sizeof policydb); sidtab_set(&sidtab, &newsidtab); security_load_policycaps(); seqno = ++latest_granting; policydb_loaded_version = policydb.policyvers; write_unlock_irq(&policy_rwlock); mutex_unlock(&load_mutex); /* Free the old policydb and SID table. */ policydb_destroy(&oldpolicydb); sidtab_destroy(&oldsidtab); avc_ss_reset(seqno); selnl_notify_policyload(seqno); selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); return 0; err: mutex_unlock(&load_mutex); sidtab_destroy(&newsidtab); policydb_destroy(&newpolicydb); return rc; } /** * security_port_sid - Obtain the SID for a port. * @protocol: protocol number * @port: port number * @out_sid: security identifier */ int security_port_sid(u8 protocol, u16 port, u32 *out_sid) { struct ocontext *c; int rc = 0; read_lock(&policy_rwlock); c = policydb.ocontexts[OCON_PORT]; while (c) { if (c->u.port.protocol == protocol && c->u.port.low_port <= port && c->u.port.high_port >= port) break; c = c->next; } if (c) { if (!c->sid[0]) { rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); if (rc) goto out; } *out_sid = c->sid[0]; } else { *out_sid = SECINITSID_PORT; } out: read_unlock(&policy_rwlock); return rc; } /** * security_netif_sid - Obtain the SID for a network interface. * @name: interface name * @if_sid: interface SID */ int security_netif_sid(char *name, u32 *if_sid) { int rc = 0; struct ocontext *c; read_lock(&policy_rwlock); c = policydb.ocontexts[OCON_NETIF]; while (c) { if (strcmp(name, c->u.name) == 0) break; c = c->next; } if (c) { if (!c->sid[0] || !c->sid[1]) { rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); if (rc) goto out; rc = sidtab_context_to_sid(&sidtab, &c->context[1], &c->sid[1]); if (rc) goto out; } *if_sid = c->sid[0]; } else *if_sid = SECINITSID_NETIF; out: read_unlock(&policy_rwlock); return rc; } static int match_ipv6_addrmask(u32 *input, u32 *addr, u32 *mask) { int i, fail = 0; for (i = 0; i < 4; i++) if (addr[i] != (input[i] & mask[i])) { fail = 1; break; } return !fail; } /** * security_node_sid - Obtain the SID for a node (host). * @domain: communication domain aka address family * @addrp: address * @addrlen: address length in bytes * @out_sid: security identifier */ int security_node_sid(u16 domain, void *addrp, u32 addrlen, u32 *out_sid) { int rc = 0; struct ocontext *c; read_lock(&policy_rwlock); switch (domain) { case AF_INET: { u32 addr; if (addrlen != sizeof(u32)) { rc = -EINVAL; goto out; } addr = *((u32 *)addrp); c = policydb.ocontexts[OCON_NODE]; while (c) { if (c->u.node.addr == (addr & c->u.node.mask)) break; c = c->next; } break; } case AF_INET6: if (addrlen != sizeof(u64) * 2) { rc = -EINVAL; goto out; } c = policydb.ocontexts[OCON_NODE6]; while (c) { if (match_ipv6_addrmask(addrp, c->u.node6.addr, c->u.node6.mask)) break; c = c->next; } break; default: *out_sid = SECINITSID_NODE; goto out; } if (c) { if (!c->sid[0]) { rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); if (rc) goto out; } *out_sid = c->sid[0]; } else { *out_sid = SECINITSID_NODE; } out: read_unlock(&policy_rwlock); return rc; } #define SIDS_NEL 25 /** * security_get_user_sids - Obtain reachable SIDs for a user. * @fromsid: starting SID * @username: username * @sids: array of reachable SIDs for user * @nel: number of elements in @sids * * Generate the set of SIDs for legal security contexts * for a given user that can be reached by @fromsid. * Set *@sids to point to a dynamically allocated * array containing the set of SIDs. Set *@nel to the * number of elements in the array. */ int security_get_user_sids(u32 fromsid, char *username, u32 **sids, u32 *nel) { struct context *fromcon, usercon; u32 *mysids = NULL, *mysids2, sid; u32 mynel = 0, maxnel = SIDS_NEL; struct user_datum *user; struct role_datum *role; struct ebitmap_node *rnode, *tnode; int rc = 0, i, j; *sids = NULL; *nel = 0; if (!ss_initialized) goto out; read_lock(&policy_rwlock); context_init(&usercon); fromcon = sidtab_search(&sidtab, fromsid); if (!fromcon) { rc = -EINVAL; goto out_unlock; } user = hashtab_search(policydb.p_users.table, username); if (!user) { rc = -EINVAL; goto out_unlock; } usercon.user = user->value; mysids = kcalloc(maxnel, sizeof(*mysids), GFP_ATOMIC); if (!mysids) { rc = -ENOMEM; goto out_unlock; } ebitmap_for_each_positive_bit(&user->roles, rnode, i) { role = policydb.role_val_to_struct[i]; usercon.role = i+1; ebitmap_for_each_positive_bit(&role->types, tnode, j) { usercon.type = j+1; if (mls_setup_user_range(fromcon, user, &usercon)) continue; rc = sidtab_context_to_sid(&sidtab, &usercon, &sid); if (rc) goto out_unlock; if (mynel < maxnel) { mysids[mynel++] = sid; } else { maxnel += SIDS_NEL; mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC); if (!mysids2) { rc = -ENOMEM; goto out_unlock; } memcpy(mysids2, mysids, mynel * sizeof(*mysids2)); kfree(mysids); mysids = mysids2; mysids[mynel++] = sid; } } } out_unlock: read_unlock(&policy_rwlock); if (rc || !mynel) { kfree(mysids); goto out; } mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL); if (!mysids2) { rc = -ENOMEM; kfree(mysids); goto out; } for (i = 0, j = 0; i < mynel; i++) { rc = avc_has_perm_noaudit(fromsid, mysids[i], SECCLASS_PROCESS, PROCESS__TRANSITION, AVC_STRICT, NULL); if (!rc) mysids2[j++] = mysids[i]; cond_resched(); } rc = 0; kfree(mysids); *sids = mysids2; *nel = j; out: return rc; } /** * security_genfs_sid - Obtain a SID for a file in a filesystem * @fstype: filesystem type * @path: path from root of mount * @sclass: file security class * @sid: SID for path * * Obtain a SID to use for a file in a filesystem that * cannot support xattr or use a fixed labeling behavior like * transition SIDs or task SIDs. */ int security_genfs_sid(const char *fstype, char *path, u16 sclass, u32 *sid) { int len; struct genfs *genfs; struct ocontext *c; int rc = 0, cmp = 0; while (path[0] == '/' && path[1] == '/') path++; read_lock(&policy_rwlock); for (genfs = policydb.genfs; genfs; genfs = genfs->next) { cmp = strcmp(fstype, genfs->fstype); if (cmp <= 0) break; } if (!genfs || cmp) { *sid = SECINITSID_UNLABELED; rc = -ENOENT; goto out; } for (c = genfs->head; c; c = c->next) { len = strlen(c->u.name); if ((!c->v.sclass || sclass == c->v.sclass) && (strncmp(c->u.name, path, len) == 0)) break; } if (!c) { *sid = SECINITSID_UNLABELED; rc = -ENOENT; goto out; } if (!c->sid[0]) { rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); if (rc) goto out; } *sid = c->sid[0]; out: read_unlock(&policy_rwlock); return rc; } /** * security_fs_use - Determine how to handle labeling for a filesystem. * @fstype: filesystem type * @behavior: labeling behavior * @sid: SID for filesystem (superblock) */ int security_fs_use( const char *fstype, unsigned int *behavior, u32 *sid) { int rc = 0; struct ocontext *c; read_lock(&policy_rwlock); c = policydb.ocontexts[OCON_FSUSE]; while (c) { if (strcmp(fstype, c->u.name) == 0) break; c = c->next; } if (c) { *behavior = c->v.behavior; if (!c->sid[0]) { rc = sidtab_context_to_sid(&sidtab, &c->context[0], &c->sid[0]); if (rc) goto out; } *sid = c->sid[0]; } else { rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, sid); if (rc) { *behavior = SECURITY_FS_USE_NONE; rc = 0; } else { *behavior = SECURITY_FS_USE_GENFS; } } out: read_unlock(&policy_rwlock); return rc; } int security_get_bools(int *len, char ***names, int **values) { int i, rc = -ENOMEM; read_lock(&policy_rwlock); *names = NULL; *values = NULL; *len = policydb.p_bools.nprim; if (!*len) { rc = 0; goto out; } *names = kcalloc(*len, sizeof(char *), GFP_ATOMIC); if (!*names) goto err; *values = kcalloc(*len, sizeof(int), GFP_ATOMIC); if (!*values) goto err; for (i = 0; i < *len; i++) { size_t name_len; (*values)[i] = policydb.bool_val_to_struct[i]->state; name_len = strlen(policydb.p_bool_val_to_name[i]) + 1; (*names)[i] = kmalloc(sizeof(char) * name_len, GFP_ATOMIC); if (!(*names)[i]) goto err; strncpy((*names)[i], policydb.p_bool_val_to_name[i], name_len); (*names)[i][name_len - 1] = 0; } rc = 0; out: read_unlock(&policy_rwlock); return rc; err: if (*names) { for (i = 0; i < *len; i++) kfree((*names)[i]); } kfree(*values); goto out; } int security_set_bools(int len, int *values) { int i, rc = 0; int lenp, seqno = 0; struct cond_node *cur; write_lock_irq(&policy_rwlock); lenp = policydb.p_bools.nprim; if (len != lenp) { rc = -EFAULT; goto out; } for (i = 0; i < len; i++) { if (!!values[i] != policydb.bool_val_to_struct[i]->state) { audit_log(current->audit_context, GFP_ATOMIC, AUDIT_MAC_CONFIG_CHANGE, "bool=%s val=%d old_val=%d auid=%u ses=%u", policydb.p_bool_val_to_name[i], !!values[i], policydb.bool_val_to_struct[i]->state, audit_get_loginuid(current), audit_get_sessionid(current)); } if (values[i]) policydb.bool_val_to_struct[i]->state = 1; else policydb.bool_val_to_struct[i]->state = 0; } for (cur = policydb.cond_list; cur != NULL; cur = cur->next) { rc = evaluate_cond_node(&policydb, cur); if (rc) goto out; } seqno = ++latest_granting; out: write_unlock_irq(&policy_rwlock); if (!rc) { avc_ss_reset(seqno); selnl_notify_policyload(seqno); selinux_xfrm_notify_policyload(); } return rc; } int security_get_bool_value(int bool) { int rc = 0; int len; read_lock(&policy_rwlock); len = policydb.p_bools.nprim; if (bool >= len) { rc = -EFAULT; goto out; } rc = policydb.bool_val_to_struct[bool]->state; out: read_unlock(&policy_rwlock); return rc; } static int security_preserve_bools(struct policydb *p) { int rc, nbools = 0, *bvalues = NULL, i; char **bnames = NULL; struct cond_bool_datum *booldatum; struct cond_node *cur; rc = security_get_bools(&nbools, &bnames, &bvalues); if (rc) goto out; for (i = 0; i < nbools; i++) { booldatum = hashtab_search(p->p_bools.table, bnames[i]); if (booldatum) booldatum->state = bvalues[i]; } for (cur = p->cond_list; cur != NULL; cur = cur->next) { rc = evaluate_cond_node(p, cur); if (rc) goto out; } out: if (bnames) { for (i = 0; i < nbools; i++) kfree(bnames[i]); } kfree(bnames); kfree(bvalues); return rc; } /* * security_sid_mls_copy() - computes a new sid based on the given * sid and the mls portion of mls_sid. */ int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid) { struct context *context1; struct context *context2; struct context newcon; char *s; u32 len; int rc = 0; if (!ss_initialized || !selinux_mls_enabled) { *new_sid = sid; goto out; } context_init(&newcon); read_lock(&policy_rwlock); context1 = sidtab_search(&sidtab, sid); if (!context1) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, sid); rc = -EINVAL; goto out_unlock; } context2 = sidtab_search(&sidtab, mls_sid); if (!context2) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, mls_sid); rc = -EINVAL; goto out_unlock; } newcon.user = context1->user; newcon.role = context1->role; newcon.type = context1->type; rc = mls_context_cpy(&newcon, context2); if (rc) goto out_unlock; /* Check the validity of the new context. */ if (!policydb_context_isvalid(&policydb, &newcon)) { rc = convert_context_handle_invalid_context(&newcon); if (rc) goto bad; } rc = sidtab_context_to_sid(&sidtab, &newcon, new_sid); goto out_unlock; bad: if (!context_struct_to_string(&newcon, &s, &len)) { audit_log(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR, "security_sid_mls_copy: invalid context %s", s); kfree(s); } out_unlock: read_unlock(&policy_rwlock); context_destroy(&newcon); out: return rc; } /** * security_net_peersid_resolve - Compare and resolve two network peer SIDs * @nlbl_sid: NetLabel SID * @nlbl_type: NetLabel labeling protocol type * @xfrm_sid: XFRM SID * * Description: * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be * resolved into a single SID it is returned via @peer_sid and the function * returns zero. Otherwise @peer_sid is set to SECSID_NULL and the function * returns a negative value. A table summarizing the behavior is below: * * | function return | @sid * ------------------------------+-----------------+----------------- * no peer labels | 0 | SECSID_NULL * single peer label | 0 | * multiple, consistent labels | 0 | * multiple, inconsistent labels | - | SECSID_NULL * */ int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type, u32 xfrm_sid, u32 *peer_sid) { int rc; struct context *nlbl_ctx; struct context *xfrm_ctx; /* handle the common (which also happens to be the set of easy) cases * right away, these two if statements catch everything involving a * single or absent peer SID/label */ if (xfrm_sid == SECSID_NULL) { *peer_sid = nlbl_sid; return 0; } /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label * is present */ if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) { *peer_sid = xfrm_sid; return 0; } /* we don't need to check ss_initialized here since the only way both * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the * security server was initialized and ss_initialized was true */ if (!selinux_mls_enabled) { *peer_sid = SECSID_NULL; return 0; } read_lock(&policy_rwlock); nlbl_ctx = sidtab_search(&sidtab, nlbl_sid); if (!nlbl_ctx) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, nlbl_sid); rc = -EINVAL; goto out_slowpath; } xfrm_ctx = sidtab_search(&sidtab, xfrm_sid); if (!xfrm_ctx) { printk(KERN_ERR "SELinux: %s: unrecognized SID %d\n", __func__, xfrm_sid); rc = -EINVAL; goto out_slowpath; } rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES); out_slowpath: read_unlock(&policy_rwlock); if (rc == 0) /* at present NetLabel SIDs/labels really only carry MLS * information so if the MLS portion of the NetLabel SID * matches the MLS portion of the labeled XFRM SID/label * then pass along the XFRM SID as it is the most * expressive */ *peer_sid = xfrm_sid; else *peer_sid = SECSID_NULL; return rc; } static int get_classes_callback(void *k, void *d, void *args) { struct class_datum *datum = d; char *name = k, **classes = args; int value = datum->value - 1; classes[value] = kstrdup(name, GFP_ATOMIC); if (!classes[value]) return -ENOMEM; return 0; } int security_get_classes(char ***classes, int *nclasses) { int rc = -ENOMEM; read_lock(&policy_rwlock); *nclasses = policydb.p_classes.nprim; *classes = kcalloc(*nclasses, sizeof(*classes), GFP_ATOMIC); if (!*classes) goto out; rc = hashtab_map(policydb.p_classes.table, get_classes_callback, *classes); if (rc < 0) { int i; for (i = 0; i < *nclasses; i++) kfree((*classes)[i]); kfree(*classes); } out: read_unlock(&policy_rwlock); return rc; } static int get_permissions_callback(void *k, void *d, void *args) { struct perm_datum *datum = d; char *name = k, **perms = args; int value = datum->value - 1; perms[value] = kstrdup(name, GFP_ATOMIC); if (!perms[value]) return -ENOMEM; return 0; } int security_get_permissions(char *class, char ***perms, int *nperms) { int rc = -ENOMEM, i; struct class_datum *match; read_lock(&policy_rwlock); match = hashtab_search(policydb.p_classes.table, class); if (!match) { printk(KERN_ERR "SELinux: %s: unrecognized class %s\n", __func__, class); rc = -EINVAL; goto out; } *nperms = match->permissions.nprim; *perms = kcalloc(*nperms, sizeof(*perms), GFP_ATOMIC); if (!*perms) goto out; if (match->comdatum) { rc = hashtab_map(match->comdatum->permissions.table, get_permissions_callback, *perms); if (rc < 0) goto err; } rc = hashtab_map(match->permissions.table, get_permissions_callback, *perms); if (rc < 0) goto err; out: read_unlock(&policy_rwlock); return rc; err: read_unlock(&policy_rwlock); for (i = 0; i < *nperms; i++) kfree((*perms)[i]); kfree(*perms); return rc; } int security_get_reject_unknown(void) { return policydb.reject_unknown; } int security_get_allow_unknown(void) { return policydb.allow_unknown; } /** * security_policycap_supported - Check for a specific policy capability * @req_cap: capability * * Description: * This function queries the currently loaded policy to see if it supports the * capability specified by @req_cap. Returns true (1) if the capability is * supported, false (0) if it isn't supported. * */ int security_policycap_supported(unsigned int req_cap) { int rc; read_lock(&policy_rwlock); rc = ebitmap_get_bit(&policydb.policycaps, req_cap); read_unlock(&policy_rwlock); return rc; } struct selinux_audit_rule { u32 au_seqno; struct context au_ctxt; }; void selinux_audit_rule_free(void *vrule) { struct selinux_audit_rule *rule = vrule; if (rule) { context_destroy(&rule->au_ctxt); kfree(rule); } } int selinux_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) { struct selinux_audit_rule *tmprule; struct role_datum *roledatum; struct type_datum *typedatum; struct user_datum *userdatum; struct selinux_audit_rule **rule = (struct selinux_audit_rule **)vrule; int rc = 0; *rule = NULL; if (!ss_initialized) return -EOPNOTSUPP; switch (field) { case AUDIT_SUBJ_USER: case AUDIT_SUBJ_ROLE: case AUDIT_SUBJ_TYPE: case AUDIT_OBJ_USER: case AUDIT_OBJ_ROLE: case AUDIT_OBJ_TYPE: /* only 'equals' and 'not equals' fit user, role, and type */ if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL) return -EINVAL; break; case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: case AUDIT_OBJ_LEV_LOW: case AUDIT_OBJ_LEV_HIGH: /* we do not allow a range, indicated by the presense of '-' */ if (strchr(rulestr, '-')) return -EINVAL; break; default: /* only the above fields are valid */ return -EINVAL; } tmprule = kzalloc(sizeof(struct selinux_audit_rule), GFP_KERNEL); if (!tmprule) return -ENOMEM; context_init(&tmprule->au_ctxt); read_lock(&policy_rwlock); tmprule->au_seqno = latest_granting; switch (field) { case AUDIT_SUBJ_USER: case AUDIT_OBJ_USER: userdatum = hashtab_search(policydb.p_users.table, rulestr); if (!userdatum) rc = -EINVAL; else tmprule->au_ctxt.user = userdatum->value; break; case AUDIT_SUBJ_ROLE: case AUDIT_OBJ_ROLE: roledatum = hashtab_search(policydb.p_roles.table, rulestr); if (!roledatum) rc = -EINVAL; else tmprule->au_ctxt.role = roledatum->value; break; case AUDIT_SUBJ_TYPE: case AUDIT_OBJ_TYPE: typedatum = hashtab_search(policydb.p_types.table, rulestr); if (!typedatum) rc = -EINVAL; else tmprule->au_ctxt.type = typedatum->value; break; case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: case AUDIT_OBJ_LEV_LOW: case AUDIT_OBJ_LEV_HIGH: rc = mls_from_string(rulestr, &tmprule->au_ctxt, GFP_ATOMIC); break; } read_unlock(&policy_rwlock); if (rc) { selinux_audit_rule_free(tmprule); tmprule = NULL; } *rule = tmprule; return rc; } /* Check to see if the rule contains any selinux fields */ int selinux_audit_rule_known(struct audit_krule *rule) { int i; for (i = 0; i < rule->field_count; i++) { struct audit_field *f = &rule->fields[i]; switch (f->type) { case AUDIT_SUBJ_USER: case AUDIT_SUBJ_ROLE: case AUDIT_SUBJ_TYPE: case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: case AUDIT_OBJ_USER: case AUDIT_OBJ_ROLE: case AUDIT_OBJ_TYPE: case AUDIT_OBJ_LEV_LOW: case AUDIT_OBJ_LEV_HIGH: return 1; } } return 0; } int selinux_audit_rule_match(u32 sid, u32 field, u32 op, void *vrule, struct audit_context *actx) { struct context *ctxt; struct mls_level *level; struct selinux_audit_rule *rule = vrule; int match = 0; if (!rule) { audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, "selinux_audit_rule_match: missing rule\n"); return -ENOENT; } read_lock(&policy_rwlock); if (rule->au_seqno < latest_granting) { audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, "selinux_audit_rule_match: stale rule\n"); match = -ESTALE; goto out; } ctxt = sidtab_search(&sidtab, sid); if (!ctxt) { audit_log(actx, GFP_ATOMIC, AUDIT_SELINUX_ERR, "selinux_audit_rule_match: unrecognized SID %d\n", sid); match = -ENOENT; goto out; } /* a field/op pair that is not caught here will simply fall through without a match */ switch (field) { case AUDIT_SUBJ_USER: case AUDIT_OBJ_USER: switch (op) { case AUDIT_EQUAL: match = (ctxt->user == rule->au_ctxt.user); break; case AUDIT_NOT_EQUAL: match = (ctxt->user != rule->au_ctxt.user); break; } break; case AUDIT_SUBJ_ROLE: case AUDIT_OBJ_ROLE: switch (op) { case AUDIT_EQUAL: match = (ctxt->role == rule->au_ctxt.role); break; case AUDIT_NOT_EQUAL: match = (ctxt->role != rule->au_ctxt.role); break; } break; case AUDIT_SUBJ_TYPE: case AUDIT_OBJ_TYPE: switch (op) { case AUDIT_EQUAL: match = (ctxt->type == rule->au_ctxt.type); break; case AUDIT_NOT_EQUAL: match = (ctxt->type != rule->au_ctxt.type); break; } break; case AUDIT_SUBJ_SEN: case AUDIT_SUBJ_CLR: case AUDIT_OBJ_LEV_LOW: case AUDIT_OBJ_LEV_HIGH: level = ((field == AUDIT_SUBJ_SEN || field == AUDIT_OBJ_LEV_LOW) ? &ctxt->range.level[0] : &ctxt->range.level[1]); switch (op) { case AUDIT_EQUAL: match = mls_level_eq(&rule->au_ctxt.range.level[0], level); break; case AUDIT_NOT_EQUAL: match = !mls_level_eq(&rule->au_ctxt.range.level[0], level); break; case AUDIT_LESS_THAN: match = (mls_level_dom(&rule->au_ctxt.range.level[0], level) && !mls_level_eq(&rule->au_ctxt.range.level[0], level)); break; case AUDIT_LESS_THAN_OR_EQUAL: match = mls_level_dom(&rule->au_ctxt.range.level[0], level); break; case AUDIT_GREATER_THAN: match = (mls_level_dom(level, &rule->au_ctxt.range.level[0]) && !mls_level_eq(level, &rule->au_ctxt.range.level[0])); break; case AUDIT_GREATER_THAN_OR_EQUAL: match = mls_level_dom(level, &rule->au_ctxt.range.level[0]); break; } } out: read_unlock(&policy_rwlock); return match; } static int (*aurule_callback)(void) = audit_update_lsm_rules; static int aurule_avc_callback(u32 event, u32 ssid, u32 tsid, u16 class, u32 perms, u32 *retained) { int err = 0; if (event == AVC_CALLBACK_RESET && aurule_callback) err = aurule_callback(); return err; } static int __init aurule_init(void) { int err; err = avc_add_callback(aurule_avc_callback, AVC_CALLBACK_RESET, SECSID_NULL, SECSID_NULL, SECCLASS_NULL, 0); if (err) panic("avc_add_callback() failed, error %d\n", err); return err; } __initcall(aurule_init); #ifdef CONFIG_NETLABEL /** * security_netlbl_cache_add - Add an entry to the NetLabel cache * @secattr: the NetLabel packet security attributes * @sid: the SELinux SID * * Description: * Attempt to cache the context in @ctx, which was derived from the packet in * @skb, in the NetLabel subsystem cache. This function assumes @secattr has * already been initialized. * */ static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr, u32 sid) { u32 *sid_cache; sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC); if (sid_cache == NULL) return; secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC); if (secattr->cache == NULL) { kfree(sid_cache); return; } *sid_cache = sid; secattr->cache->free = kfree; secattr->cache->data = sid_cache; secattr->flags |= NETLBL_SECATTR_CACHE; } /** * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID * @secattr: the NetLabel packet security attributes * @sid: the SELinux SID * * Description: * Convert the given NetLabel security attributes in @secattr into a * SELinux SID. If the @secattr field does not contain a full SELinux * SID/context then use SECINITSID_NETMSG as the foundation. If possibile the * 'cache' field of @secattr is set and the CACHE flag is set; this is to * allow the @secattr to be used by NetLabel to cache the secattr to SID * conversion for future lookups. Returns zero on success, negative values on * failure. * */ int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, u32 *sid) { int rc = -EIDRM; struct context *ctx; struct context ctx_new; if (!ss_initialized) { *sid = SECSID_NULL; return 0; } read_lock(&policy_rwlock); if (secattr->flags & NETLBL_SECATTR_CACHE) { *sid = *(u32 *)secattr->cache->data; rc = 0; } else if (secattr->flags & NETLBL_SECATTR_SECID) { *sid = secattr->attr.secid; rc = 0; } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { ctx = sidtab_search(&sidtab, SECINITSID_NETMSG); if (ctx == NULL) goto netlbl_secattr_to_sid_return; ctx_new.user = ctx->user; ctx_new.role = ctx->role; ctx_new.type = ctx->type; mls_import_netlbl_lvl(&ctx_new, secattr); if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat, secattr->attr.mls.cat) != 0) goto netlbl_secattr_to_sid_return; ctx_new.range.level[1].cat.highbit = ctx_new.range.level[0].cat.highbit; ctx_new.range.level[1].cat.node = ctx_new.range.level[0].cat.node; } else { ebitmap_init(&ctx_new.range.level[0].cat); ebitmap_init(&ctx_new.range.level[1].cat); } if (mls_context_isvalid(&policydb, &ctx_new) != 1) goto netlbl_secattr_to_sid_return_cleanup; rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid); if (rc != 0) goto netlbl_secattr_to_sid_return_cleanup; security_netlbl_cache_add(secattr, *sid); ebitmap_destroy(&ctx_new.range.level[0].cat); } else { *sid = SECSID_NULL; rc = 0; } netlbl_secattr_to_sid_return: read_unlock(&policy_rwlock); return rc; netlbl_secattr_to_sid_return_cleanup: ebitmap_destroy(&ctx_new.range.level[0].cat); goto netlbl_secattr_to_sid_return; } /** * security_netlbl_sid_to_secattr - Convert a SELinux SID to a NetLabel secattr * @sid: the SELinux SID * @secattr: the NetLabel packet security attributes * * Description: * Convert the given SELinux SID in @sid into a NetLabel security attribute. * Returns zero on success, negative values on failure. * */ int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) { int rc = -ENOENT; struct context *ctx; if (!ss_initialized) return 0; read_lock(&policy_rwlock); ctx = sidtab_search(&sidtab, sid); if (ctx == NULL) goto netlbl_sid_to_secattr_failure; secattr->domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1], GFP_ATOMIC); secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY; mls_export_netlbl_lvl(ctx, secattr); rc = mls_export_netlbl_cat(ctx, secattr); if (rc != 0) goto netlbl_sid_to_secattr_failure; read_unlock(&policy_rwlock); return 0; netlbl_sid_to_secattr_failure: read_unlock(&policy_rwlock); return rc; } #endif /* CONFIG_NETLABEL */