From e7c142a19d8b3944c2f1b9ab7fd94c63d8d0c555 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 20 Sep 2023 16:16:29 -0700 Subject: [PATCH] cmd/compile: use absolute file name in isCgo check For #23672 Fixes #63211 Fixes CVE-2023-39323 Change-Id: I4586a69e1b2560036afec29d53e53cf25e6c7352 Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/2032884 Reviewed-by: Matthew Dempsky Reviewed-by: Roland Shoemaker Reviewed-on: https://go-review.googlesource.com/c/go/+/534158 Reviewed-by: Dmitri Shuralyov Reviewed-by: Ian Lance Taylor LUCI-TryBot-Result: Go LUCI Auto-Submit: Ian Lance Taylor --- src/cmd/cgo/internal/testerrors/errors_test.go | 1 + src/cmd/cgo/internal/testerrors/testdata/err5.go | 11 +++++++++++ src/cmd/compile/internal/noder/noder.go | 8 +++++++- 3 files changed, 19 insertions(+), 1 deletion(-) create mode 100644 src/cmd/cgo/internal/testerrors/testdata/err5.go diff --git a/src/cmd/cgo/internal/testerrors/errors_test.go b/src/cmd/cgo/internal/testerrors/errors_test.go index fd522ba4745..86236249ca9 100644 --- a/src/cmd/cgo/internal/testerrors/errors_test.go +++ b/src/cmd/cgo/internal/testerrors/errors_test.go @@ -118,6 +118,7 @@ func TestReportsTypeErrors(t *testing.T) { for _, file := range []string{ "err1.go", "err2.go", + "err5.go", "issue11097a.go", "issue11097b.go", "issue18452.go", diff --git a/src/cmd/cgo/internal/testerrors/testdata/err5.go b/src/cmd/cgo/internal/testerrors/testdata/err5.go new file mode 100644 index 00000000000..c12a290d389 --- /dev/null +++ b/src/cmd/cgo/internal/testerrors/testdata/err5.go @@ -0,0 +1,11 @@ +// Copyright 2023 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package main + +//line /tmp/_cgo_.go:1 +//go:cgo_dynamic_linker "/elf/interp" +// ERROR MESSAGE: only allowed in cgo-generated code + +func main() {} diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go index 4ffc3715bef..1652dc66187 100644 --- a/src/cmd/compile/internal/noder/noder.go +++ b/src/cmd/compile/internal/noder/noder.go @@ -332,8 +332,14 @@ func (p *noder) pragma(pos syntax.Pos, blankLine bool, text string, old syntax.P // contain cgo directives, and for security reasons // (primarily misuse of linker flags), other files are not. // See golang.org/issue/23672. +// Note that cmd/go ignores files whose names start with underscore, +// so the only _cgo_ files we will see from cmd/go are generated by cgo. +// It's easy to bypass this check by calling the compiler directly; +// we only protect against uses by cmd/go. func isCgoGeneratedFile(pos syntax.Pos) bool { - return strings.HasPrefix(filepath.Base(trimFilename(pos.Base())), "_cgo_") + // We need the absolute file, independent of //line directives, + // so we call pos.Base().Pos(). + return strings.HasPrefix(filepath.Base(trimFilename(pos.Base().Pos().Base())), "_cgo_") } // safeArg reports whether arg is a "safe" command-line argument,