Merge component 'engine' from [email protected]:docker/engine 19.03

components/engine/contrib/dockerd-rootless.sh

@@ -7,7 +7,7 @@
 # External dependencies:
 # * newuidmap and newgidmap needs to be installed.
 # * /etc/subuid and /etc/subgid needs to be configured for the current user.
-# * Either one of slirp4netns (v0.3+), VPNKit, lxc-user-nic needs to be installed.
+# * Either one of slirp4netns (>= v0.4.0), VPNKit, lxc-user-nic needs to be installed.
 #   slirp4netns is used by default if installed. Otherwise fallsback to VPNKit.
 #   The default value can be overridden with $DOCKERD_ROOTLESS_ROOTLESSKIT_NET=(slirp4netns|vpnkit|lxc-user-nic)
 #
@@ -37,27 +37,27 @@ fi
 
 : "${DOCKERD_ROOTLESS_ROOTLESSKIT_NET:=}"
 : "${DOCKERD_ROOTLESS_ROOTLESSKIT_MTU:=}"
-# if slirp4netns v0.4.0+ is installed, slirp4netns is hardened using sandbox (mount namespace) and seccomp
 : "${DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX:=auto}"
 : "${DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP:=auto}"
 net=$DOCKERD_ROOTLESS_ROOTLESSKIT_NET
 mtu=$DOCKERD_ROOTLESS_ROOTLESSKIT_MTU
 if [ -z $net ]; then
 	if which slirp4netns >/dev/null 2>&1; then
-		if slirp4netns --help | grep -- --disable-host-loopback; then
+		# If --netns-type is present in --help, slirp4netns is >= v0.4.0.
+		if slirp4netns --help | grep -qw -- --netns-type; then
 			net=slirp4netns
 			if [ -z $mtu ]; then
 				mtu=65520
 			fi
 		else
-			echo "slirp4netns does not support --disable-host-loopback. Falling back to VPNKit."
+			echo "slirp4netns found but seems older than v0.4.0. Falling back to VPNKit."
 		fi
 	fi
 	if [ -z $net ]; then
 		if which vpnkit >/dev/null 2>&1; then
 			net=vpnkit
 		else
-			echo "Either slirp4netns (v0.3+) or vpnkit needs to be installed"
+			echo "Either slirp4netns (>= v0.4.0) or vpnkit needs to be installed"
 			exit 1
 		fi
 	fi

components/engine/pkg/archive/archive_linux.go

@@ -151,7 +151,9 @@ func mknodChar0Overlay(cleansedOriginalPath string) error {
 	if err := ioutil.WriteFile(lowerDummy, []byte{}, 0600); err != nil {
 		return errors.Wrapf(err, "failed to create a dummy lower file %s", lowerDummy)
 	}
-	mOpts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lower, upper, work)
+	// lowerdir needs ":" to be escaped: https://github.com/moby/moby/issues/40939#issuecomment-627098286
+	lowerEscaped := strings.ReplaceAll(lower, ":", "\\:")
+	mOpts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerEscaped, upper, work)
 	// docker/pkg/mount.Mount() requires procfs to be mounted. So we use syscall.Mount() directly instead.
 	if err := syscall.Mount("overlay", merged, "overlay", uintptr(0), mOpts); err != nil {
 		return errors.Wrapf(err, "failed to mount overlay (%s) on %s", mOpts, merged)
@@ -236,7 +238,9 @@ func createDirWithOverlayOpaque(tmp string) (string, error) {
 	if err := os.MkdirAll(lowerDummy, 0700); err != nil {
 		return "", errors.Wrapf(err, "failed to create a dummy lower directory %s", lowerDummy)
 	}
-	mOpts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lower, upper, work)
+	// lowerdir needs ":" to be escaped: https://github.com/moby/moby/issues/40939#issuecomment-627098286
+	lowerEscaped := strings.ReplaceAll(lower, ":", "\\:")
+	mOpts := fmt.Sprintf("lowerdir=%s,upperdir=%s,workdir=%s", lowerEscaped, upper, work)
 	// docker/pkg/mount.Mount() requires procfs to be mounted. So we use syscall.Mount() directly instead.
 	if err := syscall.Mount("overlay", merged, "overlay", uintptr(0), mOpts); err != nil {
 		return "", errors.Wrapf(err, "failed to mount overlay (%s) on %s", mOpts, merged)