fix FileOpRace argument access (#84)

when a call doesn't have an argument with the expected index
joernio · Jun 5, 2021 · 9814a4a · 9814a4a
1 parent d1b32c6
commit 9814a4a
Showing 1 changed file with 33 additions and 52 deletions.
diff --git a/src/main/scala/io/joern/scanners/c/FileOpRace.scala b/src/main/scala/io/joern/scanners/c/FileOpRace.scala
@@ -25,62 +25,43 @@ object FileOpRace extends QueryBundle {
         |""".stripMargin,
       score = 3.0,
       withStrRep({ cpg =>
-        val firstParam = Set(
-          "open",
-          "fopen",
-          "creat",
-          "access",
-          "chmod",
-          "readlink",
-          "chown",
-          "lchown",
-          "stat",
-          "lstat",
-          "unlink",
-          "rmdir",
-          "mkdir",
-          "mknod",
-          "mkfifo",
-          "chdir",
-          "link",
-          "rename"
+        val operations: Map[String, Seq[Integer]] = Map(
+          "access" -> Seq(1),
+          "chdir" -> Seq(1),
+          "chmod" -> Seq(1),
+          "chown" -> Seq(1),
+          "creat" -> Seq(1),
+          "faccessat" -> Seq(2),
+          "fchmodat" -> Seq(2),
+          "fopen" -> Seq(1),
+          "fstatat" -> Seq(2),
+          "lchown" -> Seq(1),
+          "linkat" -> Seq(2, 4),
+          "link" -> Seq(1, 2),
+          "lstat" -> Seq(1),
+          "mkdirat" -> Seq(2),
+          "mkdir" -> Seq(1),
+          "mkfifoat" -> Seq(2),
+          "mkfifo" -> Seq(1),
+          "mknodat" -> Seq(2),
+          "mknod" -> Seq(1),
+          "openat" -> Seq(2),
+          "open" -> Seq(1),
+          "readlinkat" -> Seq(2),
+          "readlink" -> Seq(1),
+          "renameat" -> Seq(2, 4),
+          "rename" -> Seq(1, 2),
+          "rmdir" -> Seq(1),
+          "stat" -> Seq(1),
+          "unlinkat" -> Seq(2),
+          "unlink" -> Seq(1),
         )
-        val secondParam = Set(
-          "openat",
-          "fstatat",
-          "fchmodat",
-          "readlinkat",
-          "unlinkat",
-          "mkdirat",
-          "mknodat",
-          "mkfifoat",
-          "faccessat",
-          "link",
-          "rename",
-          "linkat",
-          "renameat"
-        )
-        val fourthParam = Set("linkat", "renameat")
-
-        val anyParam = firstParam ++ secondParam ++ fourthParam
 
         def fileCalls(calls: Traversal[Call]) =
-          calls.nameExact(anyParam.toSeq: _*)
+          calls.nameExact(operations.keys.toSeq: _*)
 
-        def fileArgs(c: Call) = {
-          val res = Traversal.newBuilder[Expression]
-          // note some functions are in multiple setts because they take multiple paths
-          if (firstParam.contains(c.name)) {
-            res.addOne(c.argument(1))
-          }
-          if (secondParam.contains(c.name)) {
-            res.addOne(c.argument(2))
-          }
-          if (fourthParam.contains(c.name)) {
-            res.addOne(c.argument(4))
-          }
-          res.result().whereNot(_.isLiteral)
-        }
+        def fileArgs(c: Call) =
+          c.argument.whereNot(_.isLiteral).argumentIndex(operations(c.name): _*)
 
         fileCalls(cpg.call)
           .filter(call => {