Make UAF POI consider uses of all allocation subregions

Fixes #52.

frontend/mate/mate/poi/analysis/UseAfterFree.py

@@ -265,7 +265,7 @@ def compute_use_after_free(
         )
         .join(
             AliasEdge,
-            (AliasEdge.source == BaseAllocation.uuid) & (AliasEdge.kind == EdgeKind.MAY_ALIAS),
+            (AliasEdge.source == BaseAllocation.uuid) & (AliasEdge.kind.in_([EdgeKind.MAY_ALIAS, EdgeKind.CONTAINS])),
         )
         .join(
             LoadEdge,
@@ -311,7 +311,7 @@ def compute_use_after_free(
             )
             .join(
                 AliasEdge,
-                (AliasEdge.source == BaseAllocation.uuid) & (AliasEdge.kind == EdgeKind.MAY_ALIAS),
+                (AliasEdge.source == BaseAllocation.uuid) & (AliasEdge.kind.in_([EdgeKind.MAY_ALIAS, EdgeKind.CONTAINS])),
             )
             .join(
                 StoreEdge,
@@ -356,7 +356,7 @@ def compute_use_after_free(
             )
             .join(
                 AliasEdge,
-                (AliasEdge.source == BaseAllocation.uuid) & (AliasEdge.kind == EdgeKind.MAY_ALIAS),
+                (AliasEdge.source == BaseAllocation.uuid) & (AliasEdge.kind.in_([EdgeKind.MAY_ALIAS, EdgeKind.CONTAINS])),
             )
             .join(
                 DataflowEdge,

frontend/test/programs/ntu-uaf.c

@@ -0,0 +1,98 @@
+/*
+MIT License
+
+Copyright (c) 2019 yuawn
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include<stdio.h>
+#include<stdlib.h>
+#include<fcntl.h>
+
+
+
+void init(){
+    setvbuf(stdout,0,2,0);
+    setvbuf(stdin,0,2,0);
+    setvbuf(stderr,0,2,0);
+}
+
+int read_int(){
+    char buf[0x10];
+    __read_chk( 0 , buf , 0xf , 0x10 );
+    return atoi( buf );
+}
+
+void welcome_func(){
+    puts( "Hello ~~~" );
+}
+
+void bye_func(){
+    puts( "Bye ~~~" );
+}
+
+void menu(){
+    puts( "1. add a box" );
+    puts( "2. exit" );
+    puts( ">" );
+}
+
+struct MessageBox{
+    void (*welcome)();
+    void (*bye)();
+};
+
+void backdoor(){
+    system("sh");
+}
+
+int main(){
+
+    init();
+
+    struct MessageBox* msgbox = (struct MessageBox*) malloc( sizeof( struct MessageBox ) );
+
+    msgbox->welcome = welcome_func;
+    msgbox->bye = bye_func;
+
+    msgbox->welcome();
+    free( msgbox );
+
+    int n = 3, size;
+    char *msg;
+
+    while( n-- ){
+        printf( "Size of your message: " );
+        size = read_int();
+
+        msg = (char*) malloc( size );
+
+        printf( "Message: " );
+        read( 0 , msg , size );
+
+        printf( "Saved message: %s\n" , msg );
+
+        free( msg );
+    }
+
+    msgbox->bye();
+
+    return 0;
+}

tests/postgres/poi_analysis/use_after_free_test.py

@@ -12,7 +12,7 @@ def test_poi_use_after_free_read(cpg_db_v2):
         for (free, usage, _, _) in compute_use_after_free(cpg.session, cpg)
     }
 
-    expected = {(20, 24)}
+    expected = {(20, 24), (20, 25)}
     assert results == expected
 
 
@@ -27,7 +27,7 @@ def test_poi_use_after_free_write(cpg_db_v2):
         for (free, usage, _, _) in compute_use_after_free(cpg.session, cpg)
     }
 
-    expected = {(23, 27)}
+    expected = {(23, 27), (23, 28)}
     assert results == expected
 
 
@@ -42,5 +42,19 @@ def test_poi_use_after_free_cpp(cpg_db_v2):
         for (free, usage, _, _) in compute_use_after_free(cpg.session, cpg)
     }
 
-    expected = {(17, 21)}
+    expected = {(17, 21), (17,22)}
+    assert results == expected
+
+def test_poi_use_after_free_ntu(cpg_db_v2):
+    cpg = cpg_db_v2("ntu-uaf.c")
+
+    results = {
+        (
+            free.location["line"],
+            usage.location["line"],
+        )
+        for (free, usage, _, _) in compute_use_after_free(cpg.session, cpg)
+    }
+
+    expected = {(76, 95)}
     assert results == expected