Daniel Cashman <[email protected]> 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 <[email protected]> --- 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
