Daniel Cashman <dcashman@xxxxxxxxxxx> discovered the following:
When using cil_db multiple_decls, the different cil_attribute nodes
all point to the same underlying cil_attribute struct. This leads
to problems, though, when modifying the used value in the struct.
__cil_post_db_attr() changes the value of the field to based on
the output of cil_typeattribute_used(), for use later in
cil_typeattribute_to_policydb and cil_typeattribute_to_bitmap, but
due to the multiple declarations, cil_typeattribute_used() could be
called again by a second node. In this second call, the value used
is the modifed value of CIL_TRUE or CIL_FALSE, not the flags actually
needed. This could result in the field being reset again, to an
incorrect CIL_FALSE value.
Add the field "keep" to struct cil_typeattributeset, set its value
using cil_typeattribute_used(), and use it when determining whether
the attribute is to be kept or if it should be expanded.
Signed-off-by: James Carter <jwcart2@xxxxxxxxxxxxx>
---
libsepol/cil/src/cil.c | 1 +
libsepol/cil/src/cil_binary.c | 8 ++++----
libsepol/cil/src/cil_internal.h | 1 +
libsepol/cil/src/cil_policy.c | 2 +-
libsepol/cil/src/cil_post.c | 2 +-
libsepol/cil/src/cil_reset_ast.c | 1 +
6 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/libsepol/cil/src/cil.c b/libsepol/cil/src/cil.c
index 3fe68af8..5a64c2bc 100644
--- a/libsepol/cil/src/cil.c
+++ b/libsepol/cil/src/cil.c
@@ -2064,6 +2064,7 @@ void cil_typeattribute_init(struct cil_typeattribute **attr)
(*attr)->expr_list = NULL;
(*attr)->types = NULL;
(*attr)->used = CIL_FALSE;
+ (*attr)->keep = CIL_FALSE;
}
void cil_typeattributeset_init(struct cil_typeattributeset **attrset)
diff --git a/libsepol/cil/src/cil_binary.c b/libsepol/cil/src/cil_binary.c
index c0ca60f2..431cd9cd 100644
--- a/libsepol/cil/src/cil_binary.c
+++ b/libsepol/cil/src/cil_binary.c
@@ -567,7 +567,7 @@ int cil_typeattribute_to_policydb(policydb_t *pdb, struct cil_typeattribute *cil
char *key = NULL;
type_datum_t *sepol_attr = NULL;
- if (!cil_attr->used) {
+ if (!cil_attr->keep) {
return SEPOL_OK;
}
@@ -632,7 +632,7 @@ int cil_typeattribute_to_bitmap(policydb_t *pdb, const struct cil_db *db, struct
ebitmap_node_t *tnode;
unsigned int i;
- if (!cil_attr->used) {
+ if (!cil_attr->keep) {
return SEPOL_OK;
}
@@ -1442,7 +1442,7 @@ static int __cil_should_expand_attribute( const struct cil_db *db, struct cil_sy
attr = (struct cil_typeattribute *)datum;
- return !attr->used || (ebitmap_cardinality(attr->types) < db->attrs_expand_size);
+ return !attr->keep || (ebitmap_cardinality(attr->types) < db->attrs_expand_size);
}
int __cil_avrule_to_avtab(policydb_t *pdb, const struct cil_db *db, struct cil_avrule *cil_avrule, cond_node_t *cond_node, enum cil_flavor cond_flavor)
@@ -2525,7 +2525,7 @@ int __cil_constrain_expr_datum_to_sepol_expr(policydb_t *pdb, const struct cil_d
if (rc != SEPOL_OK) {
if (FLAVOR(item->data) == CIL_TYPEATTRIBUTE) {
struct cil_typeattribute *attr = item->data;
- if (!attr->used) {
+ if (!attr->keep) {
rc = 0;
}
}
diff --git a/libsepol/cil/src/cil_internal.h b/libsepol/cil/src/cil_internal.h
index 136a0049..8393e391 100644
--- a/libsepol/cil/src/cil_internal.h
+++ b/libsepol/cil/src/cil_internal.h
@@ -531,6 +531,7 @@ struct cil_typeattribute {
struct cil_list *expr_list;
ebitmap_t *types;
int used; // whether or not this attribute was used in a binary policy rule
+ int keep;
};
struct cil_typeattributeset {
diff --git a/libsepol/cil/src/cil_policy.c b/libsepol/cil/src/cil_policy.c
index 6d4987c4..99eb53c2 100644
--- a/libsepol/cil/src/cil_policy.c
+++ b/libsepol/cil/src/cil_policy.c
@@ -1085,7 +1085,7 @@ static void cil_typeattributes_to_policy(FILE *out, struct cil_list *types, stru
type = i1->data;
cil_list_for_each(i2, attributes) {
attribute = i2->data;
- if (!attribute->used)
+ if (!attribute->keep)
continue;
if (ebitmap_get_bit(attribute->types, type->value)) {
if (first) {
diff --git a/libsepol/cil/src/cil_post.c b/libsepol/cil/src/cil_post.c
index 3e013c97..a2122454 100644
--- a/libsepol/cil/src/cil_post.c
+++ b/libsepol/cil/src/cil_post.c
@@ -1369,7 +1369,7 @@ static int __cil_post_db_attr_helper(struct cil_tree_node *node, uint32_t *finis
rc = __evaluate_type_expression(attr, db);
if (rc != SEPOL_OK) goto exit;
}
- attr->used = cil_typeattribute_used(attr, db);
+ attr->keep = cil_typeattribute_used(attr, db);
break;
}
case CIL_ROLEATTRIBUTE: {
diff --git a/libsepol/cil/src/cil_reset_ast.c b/libsepol/cil/src/cil_reset_ast.c
index 8a13a1c1..43e6b88e 100644
--- a/libsepol/cil/src/cil_reset_ast.c
+++ b/libsepol/cil/src/cil_reset_ast.c
@@ -186,6 +186,7 @@ static void cil_reset_typeattr(struct cil_typeattribute *attr)
attr->expr_list = NULL;
}
attr->used = CIL_FALSE;
+ attr->keep = CIL_FALSE;
}
static void cil_reset_typeattributeset(struct cil_typeattributeset *tas)
--
2.13.6
