diff options
Diffstat (limited to 'security/selinux/ss/services.c')
| -rw-r--r-- | security/selinux/ss/services.c | 210 |
1 files changed, 192 insertions, 18 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index b52f923ce680..343c8ab14af0 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -88,6 +88,11 @@ static u32 latest_granting; static int context_struct_to_string(struct context *context, char **scontext, u32 *scontext_len); +static int context_struct_compute_av(struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 requested, + struct av_decision *avd); /* * Return the boolean value of a constraint expression * when it is applied to the specified source and target @@ -274,6 +279,100 @@ mls_ops: } /* + * security_boundary_permission - drops violated permissions + * on boundary constraint. + */ +static void type_attribute_bounds_av(struct context *scontext, + struct context *tcontext, + u16 tclass, + u32 requested, + struct av_decision *avd) +{ + struct context lo_scontext; + struct context lo_tcontext; + struct av_decision lo_avd; + struct type_datum *source + = policydb.type_val_to_struct[scontext->type - 1]; + struct type_datum *target + = policydb.type_val_to_struct[tcontext->type - 1]; + u32 masked = 0; + + if (source->bounds) { + memset(&lo_avd, 0, sizeof(lo_avd)); + + memcpy(&lo_scontext, scontext, sizeof(lo_scontext)); + lo_scontext.type = source->bounds; + + context_struct_compute_av(&lo_scontext, + tcontext, + tclass, + requested, + &lo_avd); + if ((lo_avd.allowed & avd->allowed) == avd->allowed) + return; /* no masked permission */ + masked = ~lo_avd.allowed & avd->allowed; + } + + if (target->bounds) { + memset(&lo_avd, 0, sizeof(lo_avd)); + + memcpy(&lo_tcontext, tcontext, sizeof(lo_tcontext)); + lo_tcontext.type = target->bounds; + + context_struct_compute_av(scontext, + &lo_tcontext, + tclass, + requested, + &lo_avd); + if ((lo_avd.allowed & avd->allowed) == avd->allowed) + return; /* no masked permission */ + masked = ~lo_avd.allowed & avd->allowed; + } + + if (source->bounds && target->bounds) { + memset(&lo_avd, 0, sizeof(lo_avd)); + /* + * lo_scontext and lo_tcontext are already + * set up. + */ + + context_struct_compute_av(&lo_scontext, + &lo_tcontext, + tclass, + requested, + &lo_avd); + if ((lo_avd.allowed & avd->allowed) == avd->allowed) + return; /* no masked permission */ + masked = ~lo_avd.allowed & avd->allowed; + } + + if (masked) { + struct audit_buffer *ab; + char *stype_name + = policydb.p_type_val_to_name[source->value - 1]; + char *ttype_name + = policydb.p_type_val_to_name[target->value - 1]; + char *tclass_name + = policydb.p_class_val_to_name[tclass - 1]; + + /* mask violated permissions */ + avd->allowed &= ~masked; + + /* notice to userspace via audit message */ + ab = audit_log_start(current->audit_context, + GFP_ATOMIC, AUDIT_SELINUX_ERR); + if (!ab) + return; + + audit_log_format(ab, "av boundary violation: " + "source=%s target=%s tclass=%s", + stype_name, ttype_name, tclass_name); + avc_dump_av(ab, tclass, masked); + audit_log_end(ab); + } +} + +/* * Compute access vectors based on a context structure pair for * the permissions in a particular class. */ @@ -356,7 +455,7 @@ static int context_struct_compute_av(struct context *scontext, avkey.source_type = i + 1; avkey.target_type = j + 1; for (node = avtab_search_node(&policydb.te_avtab, &avkey); - node != NULL; + node; node = avtab_search_node_next(node, avkey.specified)) { if (node->key.specified == AVTAB_ALLOWED) avd->allowed |= node->datum.data; @@ -404,6 +503,14 @@ static int context_struct_compute_av(struct context *scontext, PROCESS__DYNTRANSITION); } + /* + * If the given source and target types have boundary + * constraint, lazy checks have to mask any violated + * permission and notice it to userspace via audit. + */ + type_attribute_bounds_av(scontext, tcontext, + tclass, requested, avd); + return 0; inval_class: @@ -549,6 +656,69 @@ out: return rc; } +/* + * security_bounded_transition - check whether the given + * transition is directed to bounded, or not. + * It returns 0, if @newsid is bounded by @oldsid. + * Otherwise, it returns error code. + * + * @oldsid : current security identifier + * @newsid : destinated security identifier + */ +int security_bounded_transition(u32 old_sid, u32 new_sid) +{ + struct context *old_context, *new_context; + struct type_datum *type; + int index; + int rc = -EINVAL; + + read_lock(&policy_rwlock); + + old_context = sidtab_search(&sidtab, old_sid); + if (!old_context) { + printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", + __func__, old_sid); + goto out; + } + + new_context = sidtab_search(&sidtab, new_sid); + if (!new_context) { + printk(KERN_ERR "SELinux: %s: unrecognized SID %u\n", + __func__, new_sid); + goto out; + } + + /* type/domain unchaned */ + if (old_context->type == new_context->type) { + rc = 0; + goto out; + } + + index = new_context->type; + while (true) { + type = policydb.type_val_to_struct[index - 1]; + BUG_ON(!type); + + /* not bounded anymore */ + if (!type->bounds) { + rc = -EPERM; + break; + } + + /* @newsid is bounded by @oldsid */ + if (type->bounds == old_context->type) { + rc = 0; + break; + } + index = type->bounds; + } +out: + read_unlock(&policy_rwlock); + + return rc; +} + + /** * security_compute_av - Compute access vector decisions. * @ssid: source security identifier @@ -794,7 +964,7 @@ static int string_to_context_struct(struct policydb *pol, *p++ = 0; typdatum = hashtab_search(pol->p_types.table, scontextp); - if (!typdatum) + if (!typdatum || typdatum->attribute) goto out; ctx->type = typdatum->value; @@ -811,11 +981,12 @@ static int string_to_context_struct(struct policydb *pol, /* Check the validity of the new context. */ if (!policydb_context_isvalid(pol, ctx)) { rc = -EINVAL; - context_destroy(ctx); goto out; } rc = 0; out: + if (rc) + context_destroy(ctx); return rc; } @@ -868,8 +1039,7 @@ static int security_context_to_sid_core(const char *scontext, u32 scontext_len, } else if (rc) goto out; rc = sidtab_context_to_sid(&sidtab, &context, sid); - if (rc) - context_destroy(&context); + context_destroy(&context); out: read_unlock(&policy_rwlock); kfree(scontext2); @@ -1037,7 +1207,7 @@ static int security_compute_sid(u32 ssid, /* 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)) { + for (; node; node = avtab_search_node_next(node, specified)) { if (node->key.specified & AVTAB_ENABLED) { avdatum = &node->datum; break; @@ -2050,7 +2220,7 @@ int security_set_bools(int len, int *values) policydb.bool_val_to_struct[i]->state = 0; } - for (cur = policydb.cond_list; cur != NULL; cur = cur->next) { + for (cur = policydb.cond_list; cur; cur = cur->next) { rc = evaluate_cond_node(&policydb, cur); if (rc) goto out; @@ -2102,7 +2272,7 @@ static int security_preserve_bools(struct policydb *p) if (booldatum) booldatum->state = bvalues[i]; } - for (cur = p->cond_list; cur != NULL; cur = cur->next) { + for (cur = p->cond_list; cur; cur = cur->next) { rc = evaluate_cond_node(p, cur); if (rc) goto out; @@ -2737,6 +2907,7 @@ int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, if (ctx == NULL) goto netlbl_secattr_to_sid_return; + context_init(&ctx_new); ctx_new.user = ctx->user; ctx_new.role = ctx->role; ctx_new.type = ctx->type; @@ -2745,13 +2916,9 @@ int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr, 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); + memcpy(&ctx_new.range.level[1].cat, + &ctx_new.range.level[0].cat, + sizeof(ctx_new.range.level[0].cat)); } if (mls_context_isvalid(&policydb, &ctx_new) != 1) goto netlbl_secattr_to_sid_return_cleanup; @@ -2788,7 +2955,7 @@ netlbl_secattr_to_sid_return_cleanup: */ int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) { - int rc = -ENOENT; + int rc; struct context *ctx; if (!ss_initialized) @@ -2796,11 +2963,18 @@ int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr) read_lock(&policy_rwlock); ctx = sidtab_search(&sidtab, sid); - if (ctx == NULL) + if (ctx == NULL) { + rc = -ENOENT; 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; + if (secattr->domain == NULL) { + rc = -ENOMEM; + goto netlbl_sid_to_secattr_failure; + } + secattr->attr.secid = sid; + secattr->flags |= NETLBL_SECATTR_DOMAIN_CPY | NETLBL_SECATTR_SECID; mls_export_netlbl_lvl(ctx, secattr); rc = mls_export_netlbl_cat(ctx, secattr); if (rc != 0) |