From  4dae3bbe0e6a5700037bb996ae84d6f457c4f58a Mon Sep 17 00:00:00 2001
From: Bryan C. Mills <bcmills@google.com>
Date: Fri, 12 May 2023 14:15:16 -0400
Subject: [PATCH] cmd/go: disallow package directories containing newlines

Directory or file paths containing newlines may cause tools (such as
cmd/cgo) that emit "//line" or "#line" -directives to write part of
the path into non-comment lines in generated source code. If those
lines contain valid Go code, it may be injected into the resulting
binary.

(Note that Go import paths and file paths within module zip files
already could not contain newlines.)

Thanks to Juho Nurminen of Mattermost for reporting this issue.

Fixes #60167.
Fixes CVE-2023-29402.

Change-Id: I64572e9f454bce7b685d00e2e6a1c96cd33d53df
Reviewed-on: https://team-review.git.corp.google.com/c/golang/go-private/+/1882606
Reviewed-by: Roland Shoemaker <bracewell@google.com>
Run-TryBot: Roland Shoemaker <bracewell@google.com>
Reviewed-by: Russ Cox <rsc@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-on: https://go-review.googlesource.com/c/go/+/501226
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

Upstream-Status: Backport [https://github.com/golang/go/commit/4dae3bbe0e6a5700037bb996ae84d6f457c4f58a]
CVE: CVE-2023-29402

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
---
 src/cmd/go/internal/load/pkg.go               |   4 +
 src/cmd/go/internal/work/exec.go              |   6 ++
 src/cmd/go/script_test.go                     |   1 +
 .../go/testdata/script/build_cwd_newline.txt  | 100 ++++++++++++++++++
 4 files changed, 111 insertions(+)
 create mode 100644 src/cmd/go/testdata/script/build_cwd_newline.txt

diff --git a/src/cmd/go/internal/load/pkg.go b/src/cmd/go/internal/load/pkg.go
index a83cc9a..d4da86d 100644
--- a/src/cmd/go/internal/load/pkg.go
+++ b/src/cmd/go/internal/load/pkg.go
@@ -1897,6 +1897,10 @@ func (p *Package) load(ctx context.Context, opts PackageOpts, path string, stk *
		setError(fmt.Errorf("invalid input directory name %q", name))
		return
	}
+	if strings.ContainsAny(p.Dir, "\r\n") {
+		setError(fmt.Errorf("invalid package directory %q", p.Dir))
+		return
+	}

	// Build list of imported packages and full dependency list.
	imports := make([]*Package, 0, len(p.Imports))
diff --git a/src/cmd/go/internal/work/exec.go b/src/cmd/go/internal/work/exec.go
index b35caa4..b1bf347 100644
--- a/src/cmd/go/internal/work/exec.go
+++ b/src/cmd/go/internal/work/exec.go
@@ -505,6 +505,12 @@ func (b *Builder) build(ctx context.Context, a *Action) (err error) {
		b.Print(a.Package.ImportPath + "\n")
	}

+	if p.Error != nil {
+		// Don't try to build anything for packages with errors. There may be a
+		// problem with the inputs that makes the package unsafe to build.
+		return p.Error
+	}
+
	if a.Package.BinaryOnly {
		p.Stale = true
		p.StaleReason = "binary-only packages are no longer supported"
diff --git a/src/cmd/go/script_test.go b/src/cmd/go/script_test.go
index c0156d0..ce4ff37 100644
--- a/src/cmd/go/script_test.go
+++ b/src/cmd/go/script_test.go
@@ -182,6 +182,7 @@ func (ts *testScript) setup() {
		"devnull=" + os.DevNull,
		"goversion=" + goVersion(ts),
		":=" + string(os.PathListSeparator),
+		"newline=\n",
	}
	if !testenv.HasExternalNetwork() {
		ts.env = append(ts.env, "TESTGONETWORK=panic", "TESTGOVCS=panic")
diff --git a/src/cmd/go/testdata/script/build_cwd_newline.txt b/src/cmd/go/testdata/script/build_cwd_newline.txt
new file mode 100644
index 0000000..61c6966
--- /dev/null
+++ b/src/cmd/go/testdata/script/build_cwd_newline.txt
@@ -0,0 +1,100 @@
+[windows] skip 'filesystem normalizes / to \'
+[plan9] skip 'filesystem disallows \n in paths'
+
+# If the directory path containing a package to be built includes a newline,
+# the go command should refuse to even try to build the package.
+
+env DIR=$WORK${/}${newline}'package main'${newline}'func main() { panic("uh-oh")'${newline}'/*'
+
+mkdir $DIR
+cd $DIR
+exec pwd
+cp $WORK/go.mod ./go.mod
+cp $WORK/main.go ./main.go
+cp $WORK/main_test.go ./main_test.go
+
+! go build -o $devnull .
+stderr 'package example: invalid package directory .*uh-oh'
+
+! go build -o $devnull main.go
+stderr 'package command-line-arguments: invalid package directory .*uh-oh'
+
+! go run .
+stderr 'package example: invalid package directory .*uh-oh'
+
+! go run main.go
+stderr 'package command-line-arguments: invalid package directory .*uh-oh'
+
+! go test .
+stderr 'package example: invalid package directory .*uh-oh'
+
+! go test -v main.go main_test.go
+stderr 'package command-line-arguments: invalid package directory .*uh-oh'
+
+
+# Since we do preserve $PWD (or set it appropriately) for commands, and we do
+# not resolve symlinks unnecessarily, referring to the contents of the unsafe
+# directory via a safe symlink should be ok, and should not inject the data from
+# the symlink target path.
+
+[!symlink] stop 'remainder of test checks symlink behavior'
+[short] stop 'links and runs binaries'
+
+symlink $WORK${/}link -> $DIR
+
+go run $WORK${/}link${/}main.go
+! stdout panic
+! stderr panic
+stderr '^ok$'
+
+go test -v $WORK${/}link${/}main.go $WORK${/}link${/}main_test.go
+! stdout panic
+! stderr panic
+stdout '^ok$'   # 'go test' combines the test's stdout into stderr
+
+cd $WORK/link
+
+! go run $DIR${/}main.go
+stderr 'package command-line-arguments: invalid package directory .*uh-oh'
+
+go run .
+! stdout panic
+! stderr panic
+stderr '^ok$'
+
+go run main.go
+! stdout panic
+! stderr panic
+stderr '^ok$'
+
+go test -v
+! stdout panic
+! stderr panic
+stdout '^ok$'  # 'go test' combines the test's stdout into stderr
+
+go test -v .
+! stdout panic
+! stderr panic
+stdout '^ok$'  # 'go test' combines the test's stdout into stderr
+
+
+-- $WORK/go.mod --
+module example
+go 1.19
+-- $WORK/main.go --
+package main
+
+import "C"
+
+func main() {
+	/* nothing here */
+	println("ok")
+}
+-- $WORK/main_test.go --
+package main
+
+import "testing"
+
+func TestMain(*testing.M) {
+	main()
+}
--
2.40.0
