From f2f92e52f6548b3b29d561d6d334a4f1fdbd8437 Mon Sep 17 00:00:00 2001 From: Fabricio Voznika Date: Tue, 8 Sep 2020 13:58:50 -0700 Subject: Honor readonly flag for root mount Updates #1487 PiperOrigin-RevId: 330580699 --- runsc/container/container_test.go | 180 +++++++++++++++++++++++--------------- 1 file changed, 111 insertions(+), 69 deletions(-) (limited to 'runsc/container/container_test.go') diff --git a/runsc/container/container_test.go b/runsc/container/container_test.go index 6082068c7..33ada5bb9 100644 --- a/runsc/container/container_test.go +++ b/runsc/container/container_test.go @@ -41,6 +41,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/kernel/auth" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/test/testutil" + "gvisor.dev/gvisor/pkg/urpc" "gvisor.dev/gvisor/runsc/boot/platforms" "gvisor.dev/gvisor/runsc/config" "gvisor.dev/gvisor/runsc/specutils" @@ -1490,6 +1491,8 @@ func TestMountNewDir(t *testing.T) { Source: srcDir, Type: "bind", }) + // Extra points for creating the mount with a readonly root. + spec.Root.Readonly = true if err := run(spec, conf); err != nil { t.Fatalf("error running sandbox: %v", err) @@ -1499,17 +1502,17 @@ func TestMountNewDir(t *testing.T) { } func TestReadonlyRoot(t *testing.T) { - for name, conf := range configsWithVFS2(t, overlay) { + for name, conf := range configsWithVFS2(t, all...) { t.Run(name, func(t *testing.T) { - spec := testutil.NewSpecWithArgs("/bin/touch", "/foo") + spec := testutil.NewSpecWithArgs("sleep", "100") spec.Root.Readonly = true + _, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf) if err != nil { t.Fatalf("error setting up container: %v", err) } defer cleanup() - // Create, start and wait for the container. args := Args{ ID: testutil.RandomContainerID(), Spec: spec, @@ -1524,12 +1527,82 @@ func TestReadonlyRoot(t *testing.T) { t.Fatalf("error starting container: %v", err) } - ws, err := c.Wait() + // Read mounts to check that root is readonly. + out, ws, err := executeCombinedOutput(c, "/bin/sh", "-c", "mount | grep ' / '") + if err != nil || ws != 0 { + t.Fatalf("exec failed, ws: %v, err: %v", ws, err) + } + t.Logf("root mount: %q", out) + if !strings.Contains(string(out), "(ro)") { + t.Errorf("root not mounted readonly: %q", out) + } + + // Check that file cannot be created. + ws, err = execute(c, "/bin/touch", "/foo") if err != nil { - t.Fatalf("error waiting on container: %v", err) + t.Fatalf("touch file in ro mount: %v", err) } if !ws.Exited() || syscall.Errno(ws.ExitStatus()) != syscall.EPERM { - t.Fatalf("container failed, waitStatus: %v", ws) + t.Fatalf("wrong waitStatus: %v", ws) + } + }) + } +} + +func TestReadonlyMount(t *testing.T) { + for name, conf := range configsWithVFS2(t, all...) { + t.Run(name, func(t *testing.T) { + dir, err := ioutil.TempDir(testutil.TmpDir(), "ro-mount") + if err != nil { + t.Fatalf("ioutil.TempDir() failed: %v", err) + } + spec := testutil.NewSpecWithArgs("sleep", "100") + spec.Mounts = append(spec.Mounts, specs.Mount{ + Destination: dir, + Source: dir, + Type: "bind", + Options: []string{"ro"}, + }) + spec.Root.Readonly = false + + _, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf) + if err != nil { + t.Fatalf("error setting up container: %v", err) + } + defer cleanup() + + args := Args{ + ID: testutil.RandomContainerID(), + Spec: spec, + BundleDir: bundleDir, + } + c, err := New(conf, args) + if err != nil { + t.Fatalf("error creating container: %v", err) + } + defer c.Destroy() + if err := c.Start(conf); err != nil { + t.Fatalf("error starting container: %v", err) + } + + // Read mounts to check that volume is readonly. + cmd := fmt.Sprintf("mount | grep ' %s '", dir) + out, ws, err := executeCombinedOutput(c, "/bin/sh", "-c", cmd) + if err != nil || ws != 0 { + t.Fatalf("exec failed, ws: %v, err: %v", ws, err) + } + t.Logf("mount: %q", out) + if !strings.Contains(string(out), "(ro)") { + t.Errorf("volume not mounted readonly: %q", out) + } + + // Check that file cannot be created. + ws, err = execute(c, "/bin/touch", path.Join(dir, "file")) + if err != nil { + t.Fatalf("touch file in ro mount: %v", err) + } + if !ws.Exited() || syscall.Errno(ws.ExitStatus()) != syscall.EPERM { + t.Fatalf("wrong WaitStatus: %v", ws) } }) } @@ -1616,54 +1689,6 @@ func TestUIDMap(t *testing.T) { } } -func TestReadonlyMount(t *testing.T) { - for name, conf := range configsWithVFS2(t, overlay) { - t.Run(name, func(t *testing.T) { - dir, err := ioutil.TempDir(testutil.TmpDir(), "ro-mount") - spec := testutil.NewSpecWithArgs("/bin/touch", path.Join(dir, "file")) - if err != nil { - t.Fatalf("ioutil.TempDir() failed: %v", err) - } - spec.Mounts = append(spec.Mounts, specs.Mount{ - Destination: dir, - Source: dir, - Type: "bind", - Options: []string{"ro"}, - }) - spec.Root.Readonly = false - - _, bundleDir, cleanup, err := testutil.SetupContainer(spec, conf) - if err != nil { - t.Fatalf("error setting up container: %v", err) - } - defer cleanup() - - // Create, start and wait for the container. - args := Args{ - ID: testutil.RandomContainerID(), - Spec: spec, - BundleDir: bundleDir, - } - c, err := New(conf, args) - if err != nil { - t.Fatalf("error creating container: %v", err) - } - defer c.Destroy() - if err := c.Start(conf); err != nil { - t.Fatalf("error starting container: %v", err) - } - - ws, err := c.Wait() - if err != nil { - t.Fatalf("error waiting on container: %v", err) - } - if !ws.Exited() || syscall.Errno(ws.ExitStatus()) != syscall.EPERM { - t.Fatalf("container failed, waitStatus: %v", ws) - } - }) - } -} - // TestAbbreviatedIDs checks that runsc supports using abbreviated container // IDs in place of full IDs. func TestAbbreviatedIDs(t *testing.T) { @@ -2116,21 +2141,13 @@ func TestMountPropagation(t *testing.T) { // Check that mount didn't propagate to private mount. privFile := filepath.Join(priv, "mnt", "file") - execArgs := &control.ExecArgs{ - Filename: "/usr/bin/test", - Argv: []string{"test", "!", "-f", privFile}, - } - if ws, err := cont.executeSync(execArgs); err != nil || ws != 0 { + if ws, err := execute(cont, "/usr/bin/test", "!", "-f", privFile); err != nil || ws != 0 { t.Fatalf("exec: test ! -f %q, ws: %v, err: %v", privFile, ws, err) } // Check that mount propagated to slave mount. slaveFile := filepath.Join(slave, "mnt", "file") - execArgs = &control.ExecArgs{ - Filename: "/usr/bin/test", - Argv: []string{"test", "-f", slaveFile}, - } - if ws, err := cont.executeSync(execArgs); err != nil || ws != 0 { + if ws, err := execute(cont, "/usr/bin/test", "-f", slaveFile); err != nil || ws != 0 { t.Fatalf("exec: test -f %q, ws: %v, err: %v", privFile, ws, err) } } @@ -2196,11 +2213,7 @@ func TestMountSymlink(t *testing.T) { // Check that symlink was resolved and mount was created where the symlink // is pointing to. file := path.Join(target, "file") - execArgs := &control.ExecArgs{ - Filename: "/usr/bin/test", - Argv: []string{"test", "-f", file}, - } - if ws, err := cont.executeSync(execArgs); err != nil || ws != 0 { + if ws, err := execute(cont, "/usr/bin/test", "-f", file); err != nil || ws != 0 { t.Fatalf("exec: test -f %q, ws: %v, err: %v", file, ws, err) } }) @@ -2326,6 +2339,35 @@ func TestTTYField(t *testing.T) { } } +func execute(cont *Container, name string, arg ...string) (syscall.WaitStatus, error) { + args := &control.ExecArgs{ + Filename: name, + Argv: append([]string{name}, arg...), + } + return cont.executeSync(args) +} + +func executeCombinedOutput(cont *Container, name string, arg ...string) ([]byte, syscall.WaitStatus, error) { + r, w, err := os.Pipe() + if err != nil { + return nil, 0, err + } + defer r.Close() + + args := &control.ExecArgs{ + Filename: name, + Argv: append([]string{name}, arg...), + FilePayload: urpc.FilePayload{Files: []*os.File{os.Stdin, w, w}}, + } + ws, err := cont.executeSync(args) + w.Close() + if err != nil { + return nil, 0, err + } + out, err := ioutil.ReadAll(r) + return out, ws, err +} + // executeSync synchronously executes a new process. func (cont *Container) executeSync(args *control.ExecArgs) (syscall.WaitStatus, error) { pid, err := cont.Execute(args) -- cgit v1.2.3