Re: [PATCH] libsepol: reject attributes in type av rules for kernel policies

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Dec 20, 2022 at 10:44 AM Christian Göttsche
<cgzones@xxxxxxxxxxxxxx> wrote:
>
> The kernel does not support type attributes as source or target in type
> av rules (type_transition, type_member, type_change)[1].  Such rules
> should have been expanded[2].
>
> [1]: https://github.com/SELinuxProject/selinux-kernel/blob/abe3c631447dcd1ba7af972fe6f054bee6f136fa/security/selinux/ss/services.c#L1843
> [2]: https://github.com/SELinuxProject/selinux/blob/0a8c177dacdc1df96ea11bb8aa75e16c4fa82285/libsepol/src/expand.c#L1981
>
> Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>

Acked-by: James Carter <jwcart2@xxxxxxxxx>

> ---
>  libsepol/src/policydb_validate.c | 28 ++++++++++++++++++----------
>  1 file changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/libsepol/src/policydb_validate.c b/libsepol/src/policydb_validate.c
> index 521ea4ff..469c14f4 100644
> --- a/libsepol/src/policydb_validate.c
> +++ b/libsepol/src/policydb_validate.c
> @@ -770,12 +770,20 @@ bad:
>   * Functions to validate a kernel policydb
>   */
>
> -static int validate_avtab_key(const avtab_key_t *key, int conditional, validate_t flavors[])
> +static int validate_avtab_key(const avtab_key_t *key, int conditional, const policydb_t *p, validate_t flavors[])
>  {
> -       if (validate_value(key->source_type, &flavors[SYM_TYPES]))
> -               goto bad;
> -       if (validate_value(key->target_type, &flavors[SYM_TYPES]))
> -               goto bad;
> +       if (p->policy_type == POLICY_KERN && key->specified & AVTAB_TYPE) {
> +               if (validate_simpletype(key->source_type, p, flavors))
> +                       goto bad;
> +               if (validate_simpletype(key->target_type, p, flavors))
> +                       goto bad;
> +       } else {
> +               if (validate_value(key->source_type, &flavors[SYM_TYPES]))
> +                       goto bad;
> +               if (validate_value(key->target_type, &flavors[SYM_TYPES]))
> +                       goto bad;
> +       }
> +
>         if (validate_value(key->target_class, &flavors[SYM_CLASSES]))
>                 goto bad;
>         switch (0xFFF & key->specified) {
> @@ -821,7 +829,7 @@ static int validate_avtab_key_and_datum(avtab_key_t *k, avtab_datum_t *d, void *
>  {
>         map_arg_t *margs = args;
>
> -       if (validate_avtab_key(k, 0, margs->flavors))
> +       if (validate_avtab_key(k, 0, margs->policy, margs->flavors))
>                 return -1;
>
>         if ((k->specified & AVTAB_TYPE) && validate_simpletype(d->data, margs->policy, margs->flavors))
> @@ -845,13 +853,13 @@ static int validate_avtab(sepol_handle_t *handle, const avtab_t *avtab, const po
>         return 0;
>  }
>
> -static int validate_cond_av_list(sepol_handle_t *handle, const cond_av_list_t *cond_av, validate_t flavors[])
> +static int validate_cond_av_list(sepol_handle_t *handle, const cond_av_list_t *cond_av, const policydb_t *p, validate_t flavors[])
>  {
>         const struct avtab_node *avtab_ptr;
>
>         for (; cond_av; cond_av = cond_av->next) {
>                 for (avtab_ptr = cond_av->node; avtab_ptr; avtab_ptr = avtab_ptr->next) {
> -                       if (validate_avtab_key(&avtab_ptr->key, 1, flavors)) {
> +                       if (validate_avtab_key(&avtab_ptr->key, 1, p, flavors)) {
>                                 ERR(handle, "Invalid cond av list");
>                                 return -1;
>                         }
> @@ -996,9 +1004,9 @@ static int validate_cond_list(sepol_handle_t *handle, const cond_list_t *cond, c
>         for (; cond; cond = cond->next) {
>                 if (validate_cond_expr(handle, cond->expr, &flavors[SYM_BOOLS]))
>                         goto bad;
> -               if (validate_cond_av_list(handle, cond->true_list, flavors))
> +               if (validate_cond_av_list(handle, cond->true_list, p, flavors))
>                         goto bad;
> -               if (validate_cond_av_list(handle, cond->false_list, flavors))
> +               if (validate_cond_av_list(handle, cond->false_list, p, flavors))
>                         goto bad;
>                 if (validate_avrules(handle, cond->avtrue_list, 1, p, flavors))
>                         goto bad;
> --
> 2.39.0
>




[Index of Archives]     [Selinux Refpolicy]     [Linux SGX]     [Fedora Users]     [Fedora Desktop]     [Yosemite Photos]     [Yosemite Camping]     [Yosemite Campsites]     [KDE Users]     [Gnome Users]

  Powered by Linux