Update go path sanitizers and sinks

Author: Kwstubbs

go/ql/lib/change-notes/2025-07-15-path-injection-sanitizers.md

@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Remove model`CreateTemp` function, from the `os` package, as a path-injection sink due to proper sanitization by Go. Add check for `os.PathSeparator` in sanitizers for path-injection query.

go/ql/lib/ext/os.model.yml

@@ -28,7 +28,6 @@ extensions:
       - ["os", "", False, "ReadDir", "", "", "Argument[0]", "path-injection", "manual"]
       - ["os", "", False, "ReadFile", "", "", "Argument[0]", "path-injection", "manual"]
       - ["os", "", False, "MkdirTemp", "", "", "Argument[0..1]", "path-injection", "manual"]
-      - ["os", "", False, "CreateTemp", "", "", "Argument[0..1]", "path-injection", "manual"]
       - ["os", "", False, "WriteFile", "", "", "Argument[0]", "path-injection", "manual"]
       # command-injection
       - ["os", "", False, "StartProcess", "", "", "Argument[0]", "command-injection", "manual"]

go/ql/test/query-tests/Security/CWE-022/TaintedPath.expected

@@ -1,14 +1,14 @@
 #select
 | TaintedPath.go:17:29:17:40 | tainted_path | TaintedPath.go:14:18:14:22 | selection of URL | TaintedPath.go:17:29:17:40 | tainted_path | This path depends on a $@. | TaintedPath.go:14:18:14:22 | selection of URL | user-provided value |
 | TaintedPath.go:21:28:21:69 | call to Join | TaintedPath.go:14:18:14:22 | selection of URL | TaintedPath.go:21:28:21:69 | call to Join | This path depends on a $@. | TaintedPath.go:14:18:14:22 | selection of URL | user-provided value |
-| TaintedPath.go:68:28:68:57 | call to Clean | TaintedPath.go:14:18:14:22 | selection of URL | TaintedPath.go:68:28:68:57 | call to Clean | This path depends on a $@. | TaintedPath.go:14:18:14:22 | selection of URL | user-provided value |
+| TaintedPath.go:69:28:69:57 | call to Clean | TaintedPath.go:14:18:14:22 | selection of URL | TaintedPath.go:69:28:69:57 | call to Clean | This path depends on a $@. | TaintedPath.go:14:18:14:22 | selection of URL | user-provided value |
 edges
 | TaintedPath.go:14:18:14:22 | selection of URL | TaintedPath.go:14:18:14:30 | call to Query | provenance | Src:MaD:2 MaD:3 |
 | TaintedPath.go:14:18:14:30 | call to Query | TaintedPath.go:17:29:17:40 | tainted_path | provenance | Sink:MaD:1 |
 | TaintedPath.go:14:18:14:30 | call to Query | TaintedPath.go:21:57:21:68 | tainted_path | provenance |  |
-| TaintedPath.go:14:18:14:30 | call to Query | TaintedPath.go:68:39:68:56 | ...+... | provenance |  |
+| TaintedPath.go:14:18:14:30 | call to Query | TaintedPath.go:69:39:69:56 | ...+... | provenance |  |
 | TaintedPath.go:21:57:21:68 | tainted_path | TaintedPath.go:21:28:21:69 | call to Join | provenance | FunctionModel Sink:MaD:1 |
-| TaintedPath.go:68:39:68:56 | ...+... | TaintedPath.go:68:28:68:57 | call to Clean | provenance | MaD:4 Sink:MaD:1 |
+| TaintedPath.go:69:39:69:56 | ...+... | TaintedPath.go:69:28:69:57 | call to Clean | provenance | MaD:4 Sink:MaD:1 |
 models
 | 1 | Sink: io/ioutil; ; false; ReadFile; ; ; Argument[0]; path-injection; manual |
 | 2 | Source: net/http; Request; true; URL; ; ; ; remote; manual |
@@ -20,6 +20,6 @@ nodes
 | TaintedPath.go:17:29:17:40 | tainted_path | semmle.label | tainted_path |
 | TaintedPath.go:21:28:21:69 | call to Join | semmle.label | call to Join |
 | TaintedPath.go:21:57:21:68 | tainted_path | semmle.label | tainted_path |
-| TaintedPath.go:68:28:68:57 | call to Clean | semmle.label | call to Clean |
-| TaintedPath.go:68:39:68:56 | ...+... | semmle.label | ...+... |
+| TaintedPath.go:69:28:69:57 | call to Clean | semmle.label | call to Clean |
+| TaintedPath.go:69:39:69:56 | ...+... | semmle.label | ...+... |
 subpaths

go/ql/test/query-tests/Security/CWE-022/TaintedPath.go

@@ -8,8 +8,8 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
+	"os"
 )
-
 func handler(w http.ResponseWriter, r *http.Request) {
 	tainted_path := r.URL.Query()["path"][0]
 
@@ -58,9 +58,10 @@ func handler(w http.ResponseWriter, r *http.Request) {
 		w.Write(data)
 	}
 
-	// GOOD: Sanitized by filepath.Clean with a prepended '/' forcing interpretation
+	// GOOD: Sanitized by filepath.Clean with a prepended '/' or os.PathSeparator forcing interpretation
 	// as an absolute path, so that Clean will throw away any leading `..` components.
 	data, _ = ioutil.ReadFile(filepath.Clean("/" + tainted_path))
+	data, _ = ioutil.ReadFile(filepath.Clean(string(os.PathSeparator) + tainted_path))
 	w.Write(data)
 
 	// BAD: Sanitized by path.Clean with a prepended '/' forcing interpretation