Merge pull request #1594 from vrothberg/runlabel

runlabel: execute /proc/self/exe and avoid recursion

3 files changed, 16 insertions, 8 deletions

diff --git a/cmd/podman/runlabel.go b/cmd/podman/runlabel.go
index c5dd98ee6..34e6b9093 100644
--- a/cmd/podman/runlabel.go
+++ b/cmd/podman/runlabel.go
@@ -94,6 +94,14 @@ func runlabelCmd(c *cli.Context) error {
 		newImage       *image.Image
 	)
 
+	// Evil images could trick into recursively executing the runlabel
+	// command.  Avoid this by setting the "PODMAN_RUNLABEL_NESTED" env
+	// variable when executing a label first.
+	nested := os.Getenv("PODMAN_RUNLABEL_NESTED")
+	if nested == "1" {
+		return fmt.Errorf("nested runlabel calls: runlabels cannot execute the runlabel command")
+	}
+
 	opts := make(map[string]string)
 	runtime, err := libpodruntime.GetRuntime(c)
 	if err != nil {
@@ -177,6 +185,7 @@ func runlabelCmd(c *cli.Context) error {
 
 	cmd := shared.GenerateCommand(runLabel, imageName, c.String("name"))
 	env := shared.GenerateRunEnvironment(c.String("name"), imageName, opts)
+	env = append(env, "PODMAN_RUNLABEL_NESTED=1")
 
 	if !c.Bool("quiet") {
 		fmt.Printf("Command: %s\n", strings.Join(cmd, " "))
diff --git a/cmd/podman/shared/funcs.go b/cmd/podman/shared/funcs.go
index 5c401634c..21e7fe10d 100644
--- a/cmd/podman/shared/funcs.go
+++ b/cmd/podman/shared/funcs.go
@@ -15,9 +15,8 @@ func GenerateCommand(command, imageName, name string) []string {
 		name = imageName
 	}
 	cmd := strings.Split(command, " ")
-	// Replace the first position of cmd with podman whether
-	// it is docker, /usr/bin/docker, or podman
-	newCommand = append(newCommand, "podman")
+	// Replace the first element of cmd with "/proc/self/exe"
+	newCommand = append(newCommand, "/proc/self/exe")
 	for _, arg := range cmd[1:] {
 		var newArg string
 		switch arg {
diff --git a/cmd/podman/shared/funcs_test.go b/cmd/podman/shared/funcs_test.go
index 3d0ac005f..612be480b 100644
--- a/cmd/podman/shared/funcs_test.go
+++ b/cmd/podman/shared/funcs_test.go
@@ -15,35 +15,35 @@ var (
 
 func TestGenerateCommand(t *testing.T) {
 	inputCommand := "docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
-	correctCommand := "podman run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
+	correctCommand := "/proc/self/exe run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
 	newCommand := GenerateCommand(inputCommand, "foo", "bar")
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandPath(t *testing.T) {
 	inputCommand := "/usr/bin/docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
-	correctCommand := "podman run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
+	correctCommand := "/proc/self/exe run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
 	newCommand := GenerateCommand(inputCommand, "foo", "bar")
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandNoSetName(t *testing.T) {
 	inputCommand := "docker run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
-	correctCommand := "podman run -it --name foo -e NAME=foo -e IMAGE=foo foo echo install"
+	correctCommand := "/proc/self/exe run -it --name foo -e NAME=foo -e IMAGE=foo foo echo install"
 	newCommand := GenerateCommand(inputCommand, "foo", "")
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandNoName(t *testing.T) {
 	inputCommand := "docker run -it  -e IMAGE=IMAGE IMAGE echo install"
-	correctCommand := "podman run -it  -e IMAGE=foo foo echo install"
+	correctCommand := "/proc/self/exe run -it  -e IMAGE=foo foo echo install"
 	newCommand := GenerateCommand(inputCommand, "foo", "")
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }
 
 func TestGenerateCommandAlreadyPodman(t *testing.T) {
 	inputCommand := "podman run -it --name NAME -e NAME=NAME -e IMAGE=IMAGE IMAGE echo install"
-	correctCommand := "podman run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
+	correctCommand := "/proc/self/exe run -it --name bar -e NAME=bar -e IMAGE=foo foo echo install"
 	newCommand := GenerateCommand(inputCommand, "foo", "bar")
 	assert.Equal(t, correctCommand, strings.Join(newCommand, " "))
 }