On Wed, Mar 1, 2023 at 9:32 AM James Carter <jwcart2@xxxxxxxxx> wrote:
>
> On Fri, Nov 25, 2022 at 10:51 AM Christian Göttsche
> <cgzones@xxxxxxxxxxxxxx> wrote:
> >
> > Add support for using negated or complemented self in the target type of
> > neverallow rules.
> >
> > Some Refpolicy examples:
> >
> > neverallow * ~self:{ capability cap_userns capability2 cap2_userns } *;
> > neverallow domain { domain -self -dockerc_t }:dir create;
> > # no violations
> >
> > neverallow domain { domain -dockerc_t }:file ~{ append read_file_perms write };
> >
> > libsepol.report_failure: neverallow on line 584 of policy/modules/kernel/kernel.te (or line 31357 of policy.conf) violated by allow sysadm_t httpd_bugzilla_script_t:file { create setattr relabelfrom relabelto unlink link rename };
> > libsepol.report_failure: neverallow on line 584 of policy/modules/kernel/kernel.te (or line 31357 of policy.conf) violated by allow spc_t spc_t:file { create };
> > libsepol.report_failure: neverallow on line 584 of policy/modules/kernel/kernel.te (or line 31357 of policy.conf) violated by allow container_t container_t:file { create };
> > libsepol.report_failure: neverallow on line 584 of policy/modules/kernel/kernel.te (or line 31357 of policy.conf) violated by allow chromium_t chromium_t:file { create };
> > libsepol.report_failure: neverallow on line 584 of policy/modules/kernel/kernel.te (or line 31357 of policy.conf) violated by allow spc_user_t spc_user_t:file { create };
> > libsepol.report_failure: neverallow on line 582 of policy/modules/kernel/kernel.te (or line 31355 of policy.conf) violated by allow sysadm_t httpd_bugzilla_script_t:dir { create };
> >
> > neverallow domain { domain -self -dockerc_t }:file ~{ append read_file_perms write };
> >
> > libsepol.report_failure: neverallow on line 583 of policy/modules/kernel/kernel.te (or line 31356 of policy.conf) violated by allow sysadm_t httpd_bugzilla_script_t:file { create setattr relabelfrom relabelto unlink link rename };
> > libsepol.report_failure: neverallow on line 582 of policy/modules/kernel/kernel.te (or line 31355 of policy.conf) violated by allow sysadm_t httpd_bugzilla_script_t:dir { create };
> >
> > Using negated self in a complement, `~{ domain -self }`, is not
> > supported.
> >
> > Signed-off-by: Christian Göttsche <cgzones@xxxxxxxxxxxxxx>
>
> Acked-by: James Carter <jwcart2@xxxxxxxxx>
>
Merged.
Thanks,
Jim
> > ---
> > checkpolicy/policy_define.c | 46 ++++++++++++++++++++++++++++++++-----
> > checkpolicy/test/dismod.c | 6 ++++-
> > 2 files changed, 45 insertions(+), 7 deletions(-)
> >
> > diff --git a/checkpolicy/policy_define.c b/checkpolicy/policy_define.c
> > index 41e44631..74f882bb 100644
> > --- a/checkpolicy/policy_define.c
> > +++ b/checkpolicy/policy_define.c
> > @@ -2075,12 +2075,17 @@ static int define_te_avtab_xperms_helper(int which, avrule_t ** rule)
> > while ((id = queue_remove(id_queue))) {
> > if (strcmp(id, "self") == 0) {
> > free(id);
> > - if (add == 0) {
> > - yyerror("-self is not supported");
> > + if (add == 0 && which != AVRULE_XPERMS_NEVERALLOW) {
> > + yyerror("-self is only supported in neverallow and neverallowxperm rules");
> > + ret = -1;
> > + goto out;
> > + }
> > + avrule->flags |= (add ? RULE_SELF : RULE_NOTSELF);
> > + if ((avrule->flags & RULE_SELF) && (avrule->flags & RULE_NOTSELF)) {
> > + yyerror("self and -self are mutual exclusive");
> > ret = -1;
> > goto out;
> > }
> > - avrule->flags |= RULE_SELF;
> > continue;
> > }
> > if (set_types
> > @@ -2091,6 +2096,18 @@ static int define_te_avtab_xperms_helper(int which, avrule_t ** rule)
> > }
> > }
> >
> > + if ((avrule->ttypes.flags & TYPE_COMP)) {
> > + if (avrule->flags & RULE_NOTSELF) {
> > + yyerror("-self is not supported in complements");
> > + ret = -1;
> > + goto out;
> > + }
> > + if (avrule->flags & RULE_SELF) {
> > + avrule->flags &= ~RULE_SELF;
> > + avrule->flags |= RULE_NOTSELF;
> > + }
> > + }
> > +
> > ebitmap_init(&tclasses);
> > ret = read_classes(&tclasses);
> > if (ret)
> > @@ -2537,12 +2554,17 @@ static int define_te_avtab_helper(int which, avrule_t ** rule)
> > while ((id = queue_remove(id_queue))) {
> > if (strcmp(id, "self") == 0) {
> > free(id);
> > - if (add == 0) {
> > - yyerror("-self is not supported");
> > + if (add == 0 && which != AVRULE_NEVERALLOW) {
> > + yyerror("-self is only supported in neverallow and neverallowxperm rules");
> > + ret = -1;
> > + goto out;
> > + }
> > + avrule->flags |= (add ? RULE_SELF : RULE_NOTSELF);
> > + if ((avrule->flags & RULE_SELF) && (avrule->flags & RULE_NOTSELF)) {
> > + yyerror("self and -self are mutual exclusive");
> > ret = -1;
> > goto out;
> > }
> > - avrule->flags |= RULE_SELF;
> > continue;
> > }
> > if (set_types
> > @@ -2553,6 +2575,18 @@ static int define_te_avtab_helper(int which, avrule_t ** rule)
> > }
> > }
> >
> > + if ((avrule->ttypes.flags & TYPE_COMP)) {
> > + if (avrule->flags & RULE_NOTSELF) {
> > + yyerror("-self is not supported in complements");
> > + ret = -1;
> > + goto out;
> > + }
> > + if (avrule->flags & RULE_SELF) {
> > + avrule->flags &= ~RULE_SELF;
> > + avrule->flags |= RULE_NOTSELF;
> > + }
> > + }
> > +
> > ebitmap_init(&tclasses);
> > ret = read_classes(&tclasses);
> > if (ret)
> > diff --git a/checkpolicy/test/dismod.c b/checkpolicy/test/dismod.c
> > index ec2a3e9a..a2d74d42 100644
> > --- a/checkpolicy/test/dismod.c
> > +++ b/checkpolicy/test/dismod.c
> > @@ -124,7 +124,7 @@ static int display_type_set(type_set_t * set, uint32_t flags, policydb_t * polic
> > }
> >
> > num_types = 0;
> > - if (flags & RULE_SELF) {
> > + if (flags & (RULE_SELF | RULE_NOTSELF)) {
> > num_types++;
> > }
> >
> > @@ -169,6 +169,10 @@ static int display_type_set(type_set_t * set, uint32_t flags, policydb_t * polic
> > fprintf(fp, " self");
> > }
> >
> > + if (flags & RULE_NOTSELF) {
> > + fprintf(fp, " -self");
> > + }
> > +
> > if (num_types > 1)
> > fprintf(fp, " }");
> >
> > --
> > 2.38.1
> >
