From: "Christian Göttsche" <cgzones@googlemail.com>
To: selinux@vger.kernel.org
Subject: [RFC PATCH v2 3/4] checkpolicy: add not-self neverallow support
Date: Wed, 24 Nov 2021 20:08:14 +0100 [thread overview]
Message-ID: <20211124190815.12757-3-cgzones@googlemail.com> (raw)
In-Reply-To: <20211124190815.12757-1-cgzones@googlemail.com>
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 } *;
# no violations
neverallow domain domain:file ~{ append read_file_perms write };
libsepol.report_failure: neverallow on line 565 of policy/modules/kernel/kernel.te (or line 30300 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 565 of policy/modules/kernel/kernel.te (or line 30300 of policy.conf) violated by allow chromium_t chromium_t:file { create };
libsepol.report_failure: neverallow on line 564 of policy/modules/kernel/kernel.te (or line 30299 of policy.conf) violated by allow sysadm_t httpd_bugzilla_script_t:dir { create };
neverallow domain { domain -self }:file ~{ append read_file_perms write };
libsepol.report_failure: neverallow on line 565 of policy/modules/kernel/kernel.te (or line 30300 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 564 of policy/modules/kernel/kernel.te (or line 30299 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@googlemail.com>
---
v2:
- fix neverallowxperm usage
---
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 d3eb6111..f27a6f33 100644
--- a/checkpolicy/policy_define.c
+++ b/checkpolicy/policy_define.c
@@ -2067,12 +2067,17 @@ 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 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 is not supported");
ret = -1;
goto out;
}
- avrule->flags |= RULE_SELF;
continue;
}
if (set_types
@@ -2083,6 +2088,18 @@ 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)
@@ -2528,12 +2545,17 @@ 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 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 is not supported");
ret = -1;
goto out;
}
- avrule->flags |= RULE_SELF;
continue;
}
if (set_types
@@ -2544,6 +2566,18 @@ 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, " }");
--
2.34.0
next prev parent reply other threads:[~2021-11-24 19:08 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-23 19:07 [RFC PATCH 1/3] libsepol: introduce ebitmap_subtract() Christian Göttsche
2021-11-23 19:07 ` [RFC PATCH 2/3] libsepol: add not-self neverallow support Christian Göttsche
2021-11-23 19:07 ` [RFC PATCH 3/3] checkpolicy: " Christian Göttsche
2021-11-24 19:08 ` [RFC PATCH v2 1/4] libsepol: introduce ebitmap_subtract() Christian Göttsche
2021-11-24 19:08 ` [RFC PATCH v2 2/4] libsepol: add not-self neverallow support Christian Göttsche
2021-12-03 22:06 ` James Carter
2021-11-24 19:08 ` Christian Göttsche [this message]
2021-12-03 21:56 ` [RFC PATCH v2 3/4] checkpolicy: " James Carter
2021-12-04 10:45 ` Christian Göttsche
2021-11-24 19:08 ` [RFC PATCH v2 4/4] libsepol: free ebitmap on end of function Christian Göttsche
2021-11-29 17:48 ` [RFC PATCH v2 1/4] libsepol: introduce ebitmap_subtract() James Carter
2021-11-30 11:12 ` Christian Göttsche
2021-11-30 15:35 ` James Carter
2021-12-04 10:35 ` [RFC PATCH v3 1/5] libsepol: introduce ebitmap_relative_complement() Christian Göttsche
2021-12-04 10:35 ` [RFC PATCH v3 2/5] libsepol: add not-self neverallow support Christian Göttsche
2021-12-04 10:35 ` [RFC PATCH v3 3/5] checkpolicy: " Christian Göttsche
2021-12-04 10:35 ` [RFC PATCH v3 4/5] libsepol: free ebitmap on end of function Christian Göttsche
2021-12-04 10:35 ` [RFC PATCH v3 5/5] libsepol: pass avtab to report function Christian Göttsche
2021-12-06 18:25 ` James Carter
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