On Wed, Jul 13, 2022 at 10:13 AM Christian Göttsche
<cgzones@xxxxxxxxxxxxxx> wrote:
>
> Validate that
>
> - each constraint has at least one expression
> - classes reference a valid common class identifier
> - the role flavor is either ROLE or ATTRIB
> - types reference a valid primary identifier
> - types refer to a raw type, not an attribute, as bounds
> - extended permissions in avtabs have a valid specifier
> - type av rules refer to a raw type (e.g. type_transition)
> - conditionals have at least one expression
> - the state and flags of conditionals are valid
> - filename transitions have at least one datum
> - low ports are not bigger than high ones in port ocontexts
> - genfs declarations refer to a valid class identifier
> - genfs declarations contains a filesystem name
> - filename transitions refer to a raw type
> - permissive types are raw ones
> - the range transition hashmap is valid
> - the type-attribute-maps are valid
>
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
> ---
> libsepol/src/policydb_validate.c | 257 +++++++++++++++++++++++++------
> 1 file changed, 207 insertions(+), 50 deletions(-)
>
> diff --git a/libsepol/src/policydb_validate.c b/libsepol/src/policydb_validate.c
> index 0f399771..4fd8768b 100644
> --- a/libsepol/src/policydb_validate.c
> +++ b/libsepol/src/policydb_validate.c
> @@ -48,6 +48,8 @@ static int validate_init(validate_t *flavor, char **val_to_name, uint32_t nprim)
>
> static int validate_array_init(const policydb_t *p, validate_t flavors[])
> {
> + if (validate_init(&flavors[SYM_COMMONS], p->p_common_val_to_name, p->p_commons.nprim))
> + goto bad;
> if (validate_init(&flavors[SYM_CLASSES], p->p_class_val_to_name, p->p_classes.nprim))
> goto bad;
> if (validate_init(&flavors[SYM_ROLES], p->p_role_val_to_name, p->p_roles.nprim))
> @@ -235,6 +237,9 @@ static int validate_constraint_nodes(sepol_handle_t *handle, unsigned int nperms
> if (nperms > 0 && nperms != PERM_SYMTAB_SIZE && cons->permissions >= (UINT32_C(1) << nperms))
> goto bad;
>
> + if (!cons->expr)
> + goto bad;
> +
> for (cexp = cons->expr; cexp; cexp = cexp->next) {
> if (cexp->expr_type == CEXPR_NAMES) {
> if (cexp->attr & CEXPR_XTARGET && nperms != 0)
> @@ -339,10 +344,33 @@ bad:
> return -1;
> }
>
> +static int validate_common_datum(sepol_handle_t *handle, const common_datum_t *common, validate_t flavors[])
> +{
> + if (validate_value(common->s.value, &flavors[SYM_COMMONS]))
> + goto bad;
> + if (common->permissions.nprim > PERM_SYMTAB_SIZE)
> + goto bad;
> +
> + return 0;
> +
> +bad:
> + ERR(handle, "Invalid common class datum");
> + return -1;
> +}
> +
> +static int validate_common_datum_wrapper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, void *args)
> +{
> + map_arg_t *margs = args;
> +
> + return validate_common_datum(margs->handle, d, margs->flavors);
> +}
> +
> static int validate_class_datum(sepol_handle_t *handle, const class_datum_t *class, validate_t flavors[])
> {
> if (validate_value(class->s.value, &flavors[SYM_CLASSES]))
> goto bad;
> + if (class->comdatum && validate_common_datum(handle, class->comdatum, flavors))
> + goto bad;
> if (class->permissions.nprim > PERM_SYMTAB_SIZE)
> goto bad;
> if (validate_constraint_nodes(handle, class->permissions.nprim, class->constraints, flavors))
> @@ -405,25 +433,6 @@ static int validate_class_datum_wrapper(__attribute__((unused)) hashtab_key_t k,
> return validate_class_datum(margs->handle, d, margs->flavors);
> }
>
> -static int validate_common_datum(sepol_handle_t *handle, const common_datum_t *common)
> -{
> - if (common->permissions.nprim > PERM_SYMTAB_SIZE)
> - goto bad;
> -
> - return 0;
> -
> -bad:
> - ERR(handle, "Invalid common class datum");
> - return -1;
> -}
> -
> -static int validate_common_datum_wrapper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, void *args)
> -{
> - map_arg_t *margs = args;
> -
> - return validate_common_datum(margs->handle, d);
> -}
> -
> static int validate_role_datum(sepol_handle_t *handle, const role_datum_t *role, validate_t flavors[])
> {
> if (validate_value(role->s.value, &flavors[SYM_ROLES]))
> @@ -437,6 +446,14 @@ static int validate_role_datum(sepol_handle_t *handle, const role_datum_t *role,
> if (validate_ebitmap(&role->roles, &flavors[SYM_ROLES]))
> goto bad;
>
> + switch(role->flavor) {
> + case ROLE_ROLE:
> + case ROLE_ATTRIB:
> + break;
> + default:
> + goto bad;
> + }
> +
> return 0;
>
> bad:
> @@ -451,19 +468,46 @@ static int validate_role_datum_wrapper(__attribute__((unused)) hashtab_key_t k,
> return validate_role_datum(margs->handle, d, margs->flavors);
> }
>
> -static int validate_type_datum(sepol_handle_t *handle, const type_datum_t *type, validate_t flavors[])
> +static int validate_simpletype(uint32_t value, const policydb_t *p, validate_t flavors[])
> {
> - if (validate_value(type->s.value, &flavors[SYM_TYPES]))
> + const type_datum_t *type;
> +
> + if (validate_value(value, &flavors[SYM_TYPES]))
> + goto bad;
> +
> + type = p->type_val_to_struct[value - 1];
> + if (!type)
> goto bad;
> - if (validate_ebitmap(&type->types, &flavors[SYM_TYPES]))
> +
> + if (type->flavor == TYPE_ATTRIB)
> + goto bad;
> +
> + return 0;
> +
> +bad:
> + return -1;
> +}
> +
> +static int validate_type_datum(sepol_handle_t *handle, const type_datum_t *type, const policydb_t *p, validate_t flavors[])
> +{
> + if (validate_value(type->s.value, &flavors[SYM_TYPES]))
> goto bad;
> - if (type->bounds && validate_value(type->bounds, &flavors[SYM_TYPES]))
> + if (type->primary && validate_value(type->primary, &flavors[SYM_TYPES]))
> goto bad;
>
> switch (type->flavor) {
> case TYPE_TYPE:
> - case TYPE_ATTRIB:
> case TYPE_ALIAS:
> + if (!ebitmap_is_empty(&type->types))
> + goto bad;
> + if (type->bounds && validate_simpletype(type->bounds, p, flavors))
> + goto bad;
> + break;
> + case TYPE_ATTRIB:
> + if (validate_ebitmap(&type->types, &flavors[SYM_TYPES]))
> + goto bad;
> + if (type->bounds)
> + goto bad;
> break;
> default:
> goto bad;
> @@ -491,7 +535,7 @@ static int validate_type_datum_wrapper(__attribute__((unused)) hashtab_key_t k,
> {
> map_arg_t *margs = args;
>
> - return validate_type_datum(margs->handle, d, margs->flavors);
> + return validate_type_datum(margs->handle, d, margs->policy, margs->flavors);
> }
>
> static int validate_mls_semantic_cat(const mls_semantic_cat_t *cat, const validate_t *cats)
> @@ -758,22 +802,42 @@ bad:
> return -1;
> }
>
> +static int validate_xperms(const avtab_extended_perms_t *xperms)
> +{
> + switch (xperms->specified) {
> + case AVTAB_XPERMS_IOCTLDRIVER:
> + case AVTAB_XPERMS_IOCTLFUNCTION:
> + break;
> + default:
> + goto bad;
> + }
> +
> + return 0;
> +
> +bad:
> + return -1;
> +}
> static int validate_avtab_key_and_datum(avtab_key_t *k, avtab_datum_t *d, void *args)
> {
> - validate_t *flavors = (validate_t *)args;
> + map_arg_t *margs = args;
> +
> + if (validate_avtab_key(k, 0, margs->flavors))
> + return -1;
>
> - if (validate_avtab_key(k, 0, flavors))
> + if ((k->specified & AVTAB_TYPE) && validate_simpletype(d->data, margs->policy, margs->flavors))
> return -1;
>
> - if ((k->specified & AVTAB_TYPE) && validate_value(d->data, &flavors[SYM_TYPES]))
> + if ((k->specified & AVTAB_XPERMS) && validate_xperms(d->xperms))
> return -1;
>
> return 0;
> }
>
> -static int validate_avtab(sepol_handle_t *handle, const avtab_t *avtab, validate_t flavors[])
> +static int validate_avtab(sepol_handle_t *handle, const avtab_t *avtab, const policydb_t *p, validate_t flavors[])
> {
> - if (avtab_map(avtab, validate_avtab_key_and_datum, flavors)) {
> + map_arg_t margs = { flavors, handle, p };
> +
> + if (avtab_map(avtab, validate_avtab_key_and_datum, &margs)) {
> ERR(handle, "Invalid avtab");
> return -1;
> }
> @@ -797,20 +861,15 @@ static int validate_cond_av_list(sepol_handle_t *handle, const cond_av_list_t *c
> return 0;
> }
>
> -static int validate_avrules(sepol_handle_t *handle, const avrule_t *avrule, int conditional, validate_t flavors[])
> +static int validate_avrules(sepol_handle_t *handle, const avrule_t *avrule, int conditional, const policydb_t *p, validate_t flavors[])
> {
> - const class_perm_node_t *class;
> + const class_perm_node_t *classperm;
>
> for (; avrule; avrule = avrule->next) {
> if (validate_type_set(&avrule->stypes, &flavors[SYM_TYPES]))
> goto bad;
> if (validate_type_set(&avrule->ttypes, &flavors[SYM_TYPES]))
> goto bad;
> - class = avrule->perms;
> - for (; class; class = class->next) {
> - if (validate_value(class->tclass, &flavors[SYM_CLASSES]))
> - goto bad;
> - }
>
> switch(avrule->specified) {
> case AVRULE_ALLOWED:
> @@ -833,6 +892,13 @@ static int validate_avrules(sepol_handle_t *handle, const avrule_t *avrule, int
> goto bad;
> }
>
> + for (classperm = avrule->perms; classperm; classperm = classperm->next) {
> + if (validate_value(classperm->tclass, &flavors[SYM_CLASSES]))
> + goto bad;
> + if ((avrule->specified & AVRULE_TYPE) && validate_simpletype(classperm->data, p, flavors))
> + goto bad;
> + }
> +
> if (avrule->specified & AVRULE_XPERMS) {
> if (!avrule->xperms)
> goto bad;
> @@ -885,6 +951,9 @@ static int validate_cond_expr(sepol_handle_t *handle, const struct cond_expr *ex
> {
> int depth = -1;
>
> + if (!expr)
> + goto bad;
> +
> for (; expr; expr = expr->next) {
> switch(expr->expr_type) {
> case COND_BOOL:
> @@ -922,7 +991,7 @@ bad:
> return -1;
> }
>
> -static int validate_cond_list(sepol_handle_t *handle, const cond_list_t *cond, validate_t flavors[])
> +static int validate_cond_list(sepol_handle_t *handle, const cond_list_t *cond, const policydb_t *p, validate_t flavors[])
> {
> for (; cond; cond = cond->next) {
> if (validate_cond_expr(handle, cond->expr, &flavors[SYM_BOOLS]))
> @@ -931,12 +1000,28 @@ static int validate_cond_list(sepol_handle_t *handle, const cond_list_t *cond, v
> goto bad;
> if (validate_cond_av_list(handle, cond->false_list, flavors))
> goto bad;
> - if (validate_avrules(handle, cond->avtrue_list, 1, flavors))
> + if (validate_avrules(handle, cond->avtrue_list, 1, p, flavors))
> goto bad;
> - if (validate_avrules(handle, cond->avfalse_list, 1, flavors))
> + if (validate_avrules(handle, cond->avfalse_list, 1, p, flavors))
> goto bad;
> if (validate_bool_id_array(handle, cond->bool_ids, cond->nbools, &flavors[SYM_BOOLS]))
> goto bad;
> +
> + switch (cond->cur_state) {
> + case 0:
> + case 1:
> + break;
> + default:
> + goto bad;
> + }
> +
> + switch (cond->flags) {
> + case 0:
> + case COND_NODE_FLAGS_TUNABLE:
> + break;
> + default:
> + goto bad;
> + }
> }
>
> return 0;
> @@ -992,6 +1077,8 @@ static int validate_filename_trans(hashtab_key_t k, hashtab_datum_t d, void *arg
> goto bad;
> if (validate_value(ftk->tclass, &flavors[SYM_CLASSES]))
> goto bad;
> + if (!ftd)
> + goto bad;
> for (; ftd; ftd = ftd->next) {
> if (validate_ebitmap(&ftd->stypes, &flavors[SYM_TYPES]))
> goto bad;
> @@ -1046,6 +1133,10 @@ static int validate_ocontexts(sepol_handle_t *handle, const policydb_t *p, valid
> if (validate_context(&octx->context[1], flavors, p->mls))
> goto bad;
> break;
> + case OCON_PORT:
> + if (octx->u.port.low_port > octx->u.port.high_port)
> + goto bad;
> + break;
> case OCON_FSUSE:
> switch (octx->v.behavior) {
> case SECURITY_FS_USE_XATTR:
> @@ -1076,7 +1167,12 @@ static int validate_genfs(sepol_handle_t *handle, const policydb_t *p, validate_
> for (octx = genfs->head; octx; octx = octx->next) {
> if (validate_context(&octx->context[0], flavors, p->mls))
> goto bad;
> + if (octx->v.sclass && validate_value(octx->v.sclass, &flavors[SYM_CLASSES]))
> + goto bad;
> }
> +
> + if (!genfs->fstype)
> + goto bad;
> }
>
> return 0;
> @@ -1173,7 +1269,7 @@ bad:
> }
>
>
> -static int validate_filename_trans_rules(sepol_handle_t *handle, const filename_trans_rule_t *filename_trans, validate_t flavors[])
> +static int validate_filename_trans_rules(sepol_handle_t *handle, const filename_trans_rule_t *filename_trans, const policydb_t *p, validate_t flavors[])
> {
> for (; filename_trans; filename_trans = filename_trans->next) {
> if (validate_type_set(&filename_trans->stypes, &flavors[SYM_TYPES]))
> @@ -1182,7 +1278,7 @@ static int validate_filename_trans_rules(sepol_handle_t *handle, const filename_
> goto bad;
> if (validate_value(filename_trans->tclass,&flavors[SYM_CLASSES] ))
> goto bad;
> - if (validate_value(filename_trans->otype, &flavors[SYM_TYPES]))
> + if (validate_simpletype(filename_trans->otype, p, flavors))
> goto bad;
>
> /* currently only the RULE_SELF flag can be set */
> @@ -1211,15 +1307,15 @@ static int validate_symtabs(sepol_handle_t *handle, const symtab_t symtabs[], va
> return 0;
> }
>
> -static int validate_avrule_blocks(sepol_handle_t *handle, const avrule_block_t *avrule_block, validate_t flavors[])
> +static int validate_avrule_blocks(sepol_handle_t *handle, const avrule_block_t *avrule_block, const policydb_t *p, validate_t flavors[])
> {
> const avrule_decl_t *decl;
>
> for (; avrule_block; avrule_block = avrule_block->next) {
> for (decl = avrule_block->branch_list; decl != NULL; decl = decl->next) {
> - if (validate_cond_list(handle, decl->cond_list, flavors))
> + if (validate_cond_list(handle, decl->cond_list, p, flavors))
> goto bad;
> - if (validate_avrules(handle, decl->avrules, 0, flavors))
> + if (validate_avrules(handle, decl->avrules, 0, p, flavors))
> goto bad;
> if (validate_role_trans_rules(handle, decl->role_tr_rules, flavors))
> goto bad;
> @@ -1231,7 +1327,7 @@ static int validate_avrule_blocks(sepol_handle_t *handle, const avrule_block_t *
> goto bad;
> if (validate_scope_index(handle, &decl->declared, flavors))
> goto bad;
> - if (validate_filename_trans_rules(handle, decl->filename_trans_rules, flavors))
> + if (validate_filename_trans_rules(handle, decl->filename_trans_rules, p, flavors))
> goto bad;
> if (validate_symtabs(handle, decl->symtab, flavors))
> goto bad;
> @@ -1259,7 +1355,7 @@ static int validate_permissives(sepol_handle_t *handle, const policydb_t *p, val
> unsigned i;
>
> ebitmap_for_each_positive_bit(&p->permissive_map, node, i) {
> - if (validate_value(i, &flavors[SYM_TYPES]))
> + if (validate_simpletype(i, p, flavors))
> goto bad;
> }
>
> @@ -1270,6 +1366,61 @@ bad:
> return -1;
> }
>
> +static int validate_range_transition(hashtab_key_t key, hashtab_datum_t data, void *args)
> +{
> + const range_trans_t *rt = (const range_trans_t *)key;
> + const mls_range_t *r = data;
> + const map_arg_t *margs = args;
> + const validate_t *flavors = margs->flavors;
> +
> + if (validate_value(rt->source_type, &flavors[SYM_TYPES]))
> + goto bad;
> + if (validate_value(rt->target_type, &flavors[SYM_TYPES]))
> + goto bad;
> + if (validate_value(rt->target_class, &flavors[SYM_CLASSES]))
> + goto bad;
> +
> + if (validate_mls_range(r, &flavors[SYM_LEVELS], &flavors[SYM_CATS]))
> + goto bad;
> +
> + return 0;
> +
> +bad:
> + return -1;
> +}
> +
> +static int validate_range_transitions(sepol_handle_t *handle, const policydb_t *p, validate_t flavors[])
> +{
> + map_arg_t margs = { flavors, handle, p };
> +
> + if (hashtab_map(p->range_tr, validate_range_transition, &margs)) {
> + ERR(handle, "Invalid range transition");
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +static int validate_typeattr_map(sepol_handle_t *handle, const policydb_t *p, validate_t flavors[])
> +{
> + const ebitmap_t *maps = p->type_attr_map;
> + unsigned int i;
> +
> + if (p->policy_type == POLICY_KERN) {
> + for (i = 0; i < p->p_types.nprim; i++) {
> + if (validate_ebitmap(&maps[i], &flavors[SYM_TYPES]))
> + goto bad;
> + }
> + } else if (maps)
> + goto bad;
> +
> + return 0;
> +
> +bad:
> + ERR(handle, "Invalid type attr map");
> + return -1;
> +}
> +
> static int validate_properties(sepol_handle_t *handle, const policydb_t *p)
> {
> switch (p->policy_type) {
> @@ -1341,10 +1492,10 @@ int policydb_validate(sepol_handle_t *handle, const policydb_t *p)
> goto bad;
>
> if (p->policy_type == POLICY_KERN) {
> - if (validate_avtab(handle, &p->te_avtab, flavors))
> + if (validate_avtab(handle, &p->te_avtab, p, flavors))
> goto bad;
> if (p->policyvers >= POLICYDB_VERSION_BOOL)
> - if (validate_cond_list(handle, p->cond_list, flavors))
> + if (validate_cond_list(handle, p->cond_list, p, flavors))
> goto bad;
> if (validate_role_transes(handle, p->role_tr, flavors))
> goto bad;
> @@ -1354,7 +1505,7 @@ int policydb_validate(sepol_handle_t *handle, const policydb_t *p)
> if (validate_filename_trans_hashtab(handle, p->filename_trans, flavors))
> goto bad;
> } else {
> - if (validate_avrule_blocks(handle, p->global, flavors))
> + if (validate_avrule_blocks(handle, p->global, p, flavors))
> goto bad;
> }
>
> @@ -1376,6 +1527,12 @@ int policydb_validate(sepol_handle_t *handle, const policydb_t *p)
> if (validate_permissives(handle, p, flavors))
> goto bad;
>
> + if (validate_range_transitions(handle, p, flavors))
> + goto bad;
> +
> + if (validate_typeattr_map(handle, p, flavors))
> + goto bad;
> +
This causes the downgrade test to fail. It finds a gap. The problem
only occurs for policy version 19.
The following works.
if (p->policyvers > POLICYDB_VERSION_PERMISSIVE) {
if (validate_typeattr_map(handle, p, flavors))
goto bad;
}
Jim
> validate_array_destroy(flavors);
>
> return 0;
> --
> 2.36.1
>
