[PATCH] libsepol: Only apply bounds checking to source types in rules

[James Carter <jwcart2@xxxxxxxxxxxxx>]

The current bounds checking of both source and target types
requires allowing any domain that has access to the child domain
to also have the same permissions to the parent, which is undesirable.
Drop the target bounds expansion and checking.

Making this change fully functional requires a corresponding kernel
change; this change only allows one to build policies that would
otherwise violate the bounds checking on target type.  The kernel
change is required to allow the permissions at runtime.

Based on patch by Stephen Smalley.

Signed-off-by: James Carter <jwcart2@xxxxxxxxxxxxx>
---
 libsepol/src/hierarchy.c | 37 -------------------------------------
 1 file changed, 37 deletions(-)

diff --git a/libsepol/src/hierarchy.c b/libsepol/src/hierarchy.c
index 6f73195..b24b39e 100644
--- a/libsepol/src/hierarchy.c
+++ b/libsepol/src/hierarchy.c
@@ -121,18 +121,6 @@ static int bounds_expand_rule(sepol_handle_t *handle, policydb_t *p,
 		}
 	}
 
-	if (ebitmap_get_bit(&p->attr_type_map[tgt - 1], parent - 1)) {
-		avtab_key.target_type = parent;
-		ebitmap_for_each_bit(&p->attr_type_map[src - 1], tnode, i) {
-			if (!ebitmap_node_get_bit(tnode, i))
-				continue;
-			avtab_key.source_type = i + 1;
-			rc = bounds_insert_rule(handle, avtab, global, other,
-						&avtab_key, &datum);
-			if (rc) goto exit;
-		}
-	}
-
 exit:
 	return rc;
 }
@@ -329,31 +317,6 @@ static int bounds_check_rule(sepol_handle_t *handle, policydb_t *p,
 			if (rc) goto exit;
 		}
 	}
-	if (ebitmap_get_bit(&p->attr_type_map[tgt - 1], child - 1)) {
-		avtab_key.target_type = parent;
-		ebitmap_for_each_bit(&p->attr_type_map[src - 1], tnode, i) {
-			if (!ebitmap_node_get_bit(tnode, i))
-				continue;
-			avtab_key.source_type = i + 1;
-			if (avtab_key.source_type == child) {
-				/* Checked above */
-				continue;
-			}
-			d = bounds_not_covered(global_avtab, cur_avtab,
-					       &avtab_key, data);
-			if (!d) continue;
-			td = p->type_val_to_struct[i];
-			if (td && td->bounds) {
-				avtab_key.source_type = td->bounds;
-				d = bounds_not_covered(global_avtab, cur_avtab,
-						       &avtab_key, data);
-				if (!d) continue;
-			}
-			(*numbad)++;
-			rc = bounds_add_bad(handle, i+1, child, class, d, bad);
-			if (rc) goto exit;
-		}
-	}
 
 exit:
 	return rc;
-- 
2.5.5

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