feat: gate set-env/add-path and render annotation locations (#1109)

`::set-env::` and `::add-path::` let a step rewrite the environment of every later step from its own output, which the runner honoured silently. They are now refused, as GitHub has done since 2020, and `ACTIONS_ALLOW_UNSECURE_COMMANDS` opts back in per step or job. Support for that variable is new here too, and is the only opt-in, matching GitHub rather than adding a runner config key on top.

Annotations keep their source location: Gitea has no annotation store and its web UI strips command properties, so `::error file=main.go,line=12::msg` is rendered as `::error::main.go:12: msg`.

`DEVELOPMENT.md` writes down the log line encoding rules this relies on.

---------

Co-authored-by: silverwind <me@silverwind.io>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1109
Reviewed-by: silverwind <2021+silverwind@noreply.gitea.com>
Co-authored-by: bircni <bircni@icloud.com>

act/runner/action_composite.go

@@ -186,10 +186,10 @@ func (rc *RunContext) compositeExecutor(action *model.Action) *compositeSteps {
 			err := rc.newCompositeCommandExecutor(step.main())(ctx)
 
 			if err != nil {
-				logger.Errorf("%v", err)
+				logger.Errorf("##[error]%s", EscapeCommandData(err.Error()))
 				common.SetJobError(ctx, err)
 			} else if ctx.Err() != nil {
-				logger.Errorf("%v", ctx.Err())
+				logger.Errorf("##[error]%s", EscapeCommandData(ctx.Err().Error()))
 				common.SetJobError(ctx, ctx.Err())
 			}
 			return nil
@@ -248,10 +248,10 @@ func newCompositeStepLogExecutor(runStep common.Executor, stepID string) common.
 		logger := common.Logger(ctx)
 		err := runStep(ctx)
 		if err != nil {
-			logger.Errorf("%v", err)
+			logger.Errorf("##[error]%s", EscapeCommandData(err.Error()))
 			common.SetJobError(ctx, err)
 		} else if ctx.Err() != nil {
-			logger.Errorf("%v", ctx.Err())
+			logger.Errorf("##[error]%s", EscapeCommandData(ctx.Err().Error()))
 			common.SetJobError(ctx, ctx.Err())
 		}
 		return nil

act/runner/command.go

@@ -6,6 +6,7 @@ package runner
 
 import (
 	"context"
+	"fmt"
 	"regexp"
 	"strings"
 
@@ -45,17 +46,24 @@ func (rc *RunContext) commandHandler(ctx context.Context) common.LineHandler {
 			return true
 		}
 
-		if resumeCommand != "" && command != resumeCommand {
+		if resumeCommand != "" {
 			// There should not be any emojis in the log output for Gitea.
-			// The code in the switch statement is the same.
 			// Return true (not false) so the line still reaches the raw_output
 			// log handler; otherwise everything between ::stop-commands:: and
 			// its end token is silently dropped from the step log.
 			logger.Infof("%s", line)
+			// Resumed here rather than from the switch, because the end token is arbitrary
+			// and a token naming a real command would otherwise never resume.
+			if command == resumeCommand {
+				resumeCommand = ""
+			}
 			return true
 		}
 		arg = UnescapeCommandData(arg)
 		kvPairs = unescapeKvPairs(kvPairs)
+		if (command == "set-env" || command == "add-path") && rc.refuseUnsecureCommand(ctx, command) {
+			return true
+		}
 		switch command {
 		case "set-env":
 			rc.setEnv(ctx, kvPairs, arg)
@@ -63,27 +71,20 @@ func (rc *RunContext) commandHandler(ctx context.Context) common.LineHandler {
 			rc.setOutput(ctx, kvPairs, arg)
 		case "add-path":
 			rc.addPath(ctx, arg)
-		case "debug":
-			logger.Infof("%s", line)
-		case "warning":
-			logger.Infof("%s", line)
-		case "error":
-			logger.Infof("%s", line)
 		case "add-mask":
 			rc.AddMask(arg)
 			logger.Infof("%s", "***")
+			// The raw line is still forwarded, carrying the secret: that is how the reporter
+			// learns the mask, and it drops the row rather than writing it out.
 		case "stop-commands":
 			resumeCommand = arg
 			logger.Infof("%s", line)
-		case resumeCommand:
-			resumeCommand = ""
-			logger.Infof("%s", line)
 		case "save-state":
 			logger.Infof("%s", line)
 			rc.saveState(ctx, kvPairs, arg)
-		case "add-matcher":
-			logger.Infof("%s", line)
 		default:
+			// ::debug::, ::error::, ::warning::, ::add-matcher:: and anything unrecognised are
+			// passed through for the reporter and Gitea's web UI to render.
 			logger.Infof("%s", line)
 		}
 
@@ -92,6 +93,52 @@ func (rc *RunContext) commandHandler(ctx context.Context) common.LineHandler {
 	}
 }
 
+const allowUnsecureCommandsVar = "ACTIONS_ALLOW_UNSECURE_COMMANDS"
+
+// refuseUnsecureCommand reports whether a deprecated ::set-env:: or ::add-path:: command must
+// not run, recording the error that fails the step. GitHub disabled both because a step that
+// echoes untrusted content can use them to set NODE_OPTIONS or PATH for every later step.
+func (rc *RunContext) refuseUnsecureCommand(ctx context.Context, command string) bool {
+	if rc.allowUnsecureCommandsOptIn() {
+		return false
+	}
+
+	// The step executor logs the failure itself, so keep this line's wording distinct.
+	common.Logger(ctx).WithField(rawOutputField, true).Errorf("##[error]%s", EscapeCommandData(fmt.Sprintf(
+		"The `%s` command is disabled: it can set the environment of every later step from untrusted output. "+
+			"Write to $GITHUB_ENV or $GITHUB_PATH instead, or set ACTIONS_ALLOW_UNSECURE_COMMANDS to allow it",
+		command)))
+
+	rc.unsecureCommandMu.Lock()
+	defer rc.unsecureCommandMu.Unlock()
+	if rc.unsecureCommandErr == nil {
+		rc.unsecureCommandErr = fmt.Errorf("the `%s` workflow command is disabled", command)
+	}
+	return true
+}
+
+// allowUnsecureCommandsOptIn reports whether the workflow itself asked for the deprecated
+// commands, from any env scope, as it can on GitHub.
+func (rc *RunContext) allowUnsecureCommandsOptIn() bool {
+	return isTruthyEnv(rc.currentStepEnv()[allowUnsecureCommandsVar]) ||
+		isTruthyEnv(rc.Env[allowUnsecureCommandsVar]) ||
+		isTruthyEnv(rc.GlobalEnv[allowUnsecureCommandsVar])
+}
+
+// isTruthyEnv mirrors GitHub's bool.TryParse: only "true", in any casing.
+func isTruthyEnv(v string) bool {
+	return strings.EqualFold(strings.TrimSpace(v), "true")
+}
+
+// takeUnsecureCommandError returns and clears the error left by a refused command.
+func (rc *RunContext) takeUnsecureCommandError() error {
+	rc.unsecureCommandMu.Lock()
+	defer rc.unsecureCommandMu.Unlock()
+	err := rc.unsecureCommandErr
+	rc.unsecureCommandErr = nil
+	return err
+}
+
 func (rc *RunContext) setEnv(ctx context.Context, kvPairs map[string]string, arg string) {
 	name := kvPairs["name"]
 	common.Logger(ctx).Infof("::set-env:: %s=%s", name, arg)
@@ -161,9 +208,9 @@ var (
 	commandPropertyUnescaper = strings.NewReplacer("%25", "%", "%0D", "\r", "%0A", "\n", "%3A", ":", "%2C", ",")
 )
 
-// escapeCommandData encodes the data part of a "::cmd::" or "##[cmd]" line the runner writes itself,
+// EscapeCommandData encodes the data part of a "::cmd::" or "##[cmd]" line the runner writes itself,
 // so the log renderer decodes it back. Lines forwarded from step output are already escaped.
-func escapeCommandData(arg string) string {
+func EscapeCommandData(arg string) string {
 	return commandDataEscaper.Replace(arg)
 }
 

act/runner/command_test.go

@@ -16,12 +16,18 @@ import (
 
 	"github.com/sirupsen/logrus/hooks/test"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
+// unsecureRC opts into ::set-env:: and ::add-path::, which are refused without it.
+func unsecureRC() *RunContext {
+	return &RunContext{Env: map[string]string{allowUnsecureCommandsVar: "true"}}
+}
+
 func TestSetEnv(t *testing.T) {
 	a := assert.New(t)
 	ctx := context.Background()
-	rc := new(RunContext)
+	rc := unsecureRC()
 	handler := rc.commandHandler(ctx)
 
 	handler("::set-env name=x::valz\n")
@@ -31,7 +37,7 @@ func TestSetEnv(t *testing.T) {
 func TestStopCommandsKeepsSuppressedLinesInLog(t *testing.T) {
 	a := assert.New(t)
 	ctx := context.Background()
-	rc := new(RunContext)
+	rc := unsecureRC()
 	handler := rc.commandHandler(ctx)
 
 	// Stop command processing until the matching end token is seen.
@@ -84,7 +90,7 @@ func TestSetOutput(t *testing.T) {
 func TestAddpath(t *testing.T) {
 	a := assert.New(t)
 	ctx := context.Background()
-	rc := new(RunContext)
+	rc := unsecureRC()
 	handler := rc.commandHandler(ctx)
 
 	handler("::add-path::/zoo\n")
@@ -99,7 +105,7 @@ func TestStopCommands(t *testing.T) {
 
 	a := assert.New(t)
 	ctx := common.WithLogger(context.Background(), logger)
-	rc := new(RunContext)
+	rc := unsecureRC()
 	handler := rc.commandHandler(ctx)
 
 	handler("::set-env name=x::valz\n")
@@ -119,10 +125,26 @@ func TestStopCommands(t *testing.T) {
 	a.Contains(messages, "::set-env name=x::abcd\n")
 }
 
+// The end token is arbitrary, so one that happens to name a real command must still resume
+// rather than being swallowed by that command's case.
+func TestStopCommandsResumesOnCommandNamedToken(t *testing.T) {
+	a := assert.New(t)
+	rc := unsecureRC()
+	handler := rc.commandHandler(context.Background())
+
+	handler("::stop-commands::add-mask\n")
+	handler("::set-env name=x::suppressed\n")
+	a.NotContains(rc.Env, "x")
+
+	handler("::add-mask::\n")
+	handler("::set-env name=x::resumed\n")
+	a.Equal("resumed", rc.Env["x"])
+}
+
 func TestAddpathADO(t *testing.T) {
 	a := assert.New(t)
 	ctx := context.Background()
-	rc := new(RunContext)
+	rc := unsecureRC()
 	handler := rc.commandHandler(ctx)
 
 	handler("##[add-path]/zoo\n")
@@ -218,6 +240,44 @@ func TestSaveState(t *testing.T) {
 func TestEscapeCommandData(t *testing.T) {
 	a := assert.New(t)
 
-	a.Equal("a%25b%0Dc%0Ad%250A", escapeCommandData("a%b\rc\nd%0A"))
+	a.Equal("a%25b%0Dc%0Ad%250A", EscapeCommandData("a%b\rc\nd%0A"))
 	a.Equal("a%b\rc\nd%0A", UnescapeCommandData("a%25b%0Dc%0Ad%250A"))
 }
+
+func TestUnsecureCommands(t *testing.T) {
+	tests := []struct {
+		name    string
+		jobEnv  map[string]string
+		stepEnv map[string]string
+		optedIn bool
+	}{
+		{name: "refused with no opt-in"},
+		// GitHub reads the opt-in with bool.TryParse, so "1" is not one.
+		{name: "refused for a value bool.TryParse rejects", jobEnv: map[string]string{allowUnsecureCommandsVar: "1"}},
+		{name: "opted in through the step environment", stepEnv: map[string]string{allowUnsecureCommandsVar: "true"}, optedIn: true},
+		{name: "opted in through the job environment", jobEnv: map[string]string{allowUnsecureCommandsVar: "TRUE"}, optedIn: true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := assert.New(t)
+			rc := &RunContext{Env: tt.jobEnv}
+			rc.setCurrentStepEnv(tt.stepEnv)
+			handler := rc.commandHandler(context.Background())
+
+			handler("::set-env name=x::valz\n")
+			handler("::add-path::/opt/bin\n")
+
+			if !tt.optedIn {
+				a.Empty(rc.Env["x"])
+				a.Empty(rc.ExtraPath)
+				// The refusal fails the step that produced it, once.
+				require.ErrorContains(t, rc.takeUnsecureCommandError(), "set-env")
+				a.NoError(rc.takeUnsecureCommandError())
+				return
+			}
+			a.Equal("valz", rc.Env["x"])
+			a.Equal([]string{"/opt/bin"}, rc.ExtraPath)
+			a.NoError(rc.takeUnsecureCommandError())
+		})
+	}
+}

act/runner/job_executor.go

@@ -66,7 +66,7 @@ func reportStepError(ctx context.Context, rc *RunContext, err error) {
 		rc.markInterrupted(ctx.Err())
 		return
 	}
-	common.Logger(ctx).Errorf("##[error]%s", escapeCommandData(err.Error()))
+	common.Logger(ctx).Errorf("##[error]%s", EscapeCommandData(err.Error()))
 	common.SetJobError(ctx, err)
 	rc.markFailed()
 }
@@ -260,7 +260,7 @@ func newJobExecutor(info jobInfo, sf stepFactory, rc *RunContext) common.Executo
 
 			logger.Infof("Cleaning up container for job %s", rc.JobName)
 			if err = info.stopContainer()(ctx); err != nil {
-				logger.Errorf("Error while stop job container: %v", err)
+				logger.Errorf("##[error]%s", EscapeCommandData("Error while stop job container: "+err.Error()))
 			}
 
 			// For Gitea

act/runner/job_hooks.go

@@ -45,7 +45,7 @@ func (rc *RunContext) runJobHook(ctx context.Context, hookPath, name string) err
 	cmd, shell := hookCommand(hookPath)
 	rawLogger := common.Logger(ctx).WithField(rawOutputField, true)
 	defer rawLogger.Infof("::endgroup::")
-	rawLogger.Infof("::group::Run '%s'", escapeCommandData(hookPath))
+	rawLogger.Infof("::group::Run '%s'", EscapeCommandData(hookPath))
 	rawLogger.Infof("A %s hook has been configured by the runner administrator", name)
 	if shell != "" {
 		rawLogger.Infof("shell: %s", shell)

act/runner/logger.go

@@ -250,7 +250,7 @@ func AppendSecretMasker(oldnew []string, v string) []string {
 			ret = append(ret, tm, "***")
 			// command data reaches the log escaped, so "pass%word" also arrives as "pass%25word"
 			if strings.ContainsAny(tm, "%\r\n") {
-				ret = append(ret, escapeCommandData(tm), "***")
+				ret = append(ret, EscapeCommandData(tm), "***")
 			}
 		}
 	}

act/runner/run_context.go

@@ -22,6 +22,7 @@ import (
 	"runtime"
 	"slices"
 	"strings"
+	"sync"
 	"time"
 
 	"gitea.com/gitea/runner/act/common"
@@ -83,6 +84,25 @@ type RunContext struct {
 	// failures. Those failures must still make success() false and failure() true for later
 	// main-step if evaluation.
 	jobFailed bool
+	// stepEnv is a copy of the running step's environment, so that workflow commands parsed out
+	// of the container's output can be judged against it. Written by runStepExecutor and read on
+	// the log-writer goroutine, hence unsecureCommandMu, which also guards unsecureCommandErr.
+	stepEnv            map[string]string
+	unsecureCommandErr error // refused ::set-env::/::add-path::, turned into a step failure
+	unsecureCommandMu  sync.Mutex
+}
+
+// setCurrentStepEnv records the environment of the step about to run.
+func (rc *RunContext) setCurrentStepEnv(env map[string]string) {
+	rc.unsecureCommandMu.Lock()
+	defer rc.unsecureCommandMu.Unlock()
+	rc.stepEnv = env
+}
+
+func (rc *RunContext) currentStepEnv() map[string]string {
+	rc.unsecureCommandMu.Lock()
+	defer rc.unsecureCommandMu.Unlock()
+	return rc.stepEnv
 }
 
 // markCancelled flags the job as cancelled so subsequent step `if` evaluations and the

act/runner/step.go

@@ -165,9 +165,22 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 		}
 		_ = rc.JobContainer.Copy(actPath, files...)(ctx)
 
+		// The command handler needs the step's env to judge ACTIONS_ALLOW_UNSECURE_COMMANDS.
+		// Cloned: the step executor keeps writing to its own env map after this point, on a
+		// different goroutine from the command handler that reads it.
+		rc.setCurrentStepEnv(maps0.Clone(*step.getEnv()))
+		defer rc.setCurrentStepEnv(nil)
+		_ = rc.takeUnsecureCommandError() // a refusal from before any step belongs to no step
+
 		timeoutctx, cancelTimeOut := evaluateStepTimeout(ctx, rc.ExprEval, stepModel)
 		defer cancelTimeOut()
 		err = executor(timeoutctx)
+		// Always take it, so the job-scoped error cannot leak onto a later step. A refusal
+		// fails the step as it does on GitHub, but the executor's own error wins.
+		insecureErr := rc.takeUnsecureCommandError()
+		if err == nil {
+			err = insecureErr
+		}
 
 		if err == nil {
 			logger.WithField("stepResult", stepResult.Outcome).Infof("Success - %s %s", stage, stepString)
@@ -181,7 +194,7 @@ func runStepExecutor(step step, stage stepStage, executor common.Executor) commo
 			}
 
 			if continueOnError {
-				logger.Errorf("##[error]%s", escapeCommandData(err.Error()))
+				logger.Errorf("##[error]%s", EscapeCommandData(err.Error()))
 				logger.Infof("Failed but continue next step")
 				err = nil
 				stepResult.Conclusion = model.StepStatusSuccess

act/runner/step_run.go

@@ -18,6 +18,7 @@ import (
 	"gitea.com/gitea/runner/act/model"
 
 	"github.com/kballard/go-shellquote"
+	"github.com/sirupsen/logrus"
 	yaml "go.yaml.in/yaml/v4"
 )
 
@@ -63,7 +64,7 @@ func (sr *stepRun) printRunScriptActionDetails(ctx context.Context) {
 
 	normalized := strings.TrimRight(strings.ReplaceAll(sr.interpolatedScript, "\r\n", "\n"), "\n")
 
-	rawLogger.Infof("::group::Run %s", escapeCommandData(sr.runScriptGroupTitle(normalized)))
+	rawLogger.Infof("::group::Run %s", EscapeCommandData(sr.runScriptGroupTitle(normalized)))
 
 	if normalized != "" {
 		for line := range strings.SplitSeq(normalized, "\n") {
@@ -90,12 +91,12 @@ func printRunActionHeader(ctx context.Context, step *model.Step, env map[string]
 	if step.Name != "" {
 		title = step.Name
 	}
-	rawLogger.Infof("::group::Run %s", escapeCommandData(title))
+	rawLogger.Infof("::group::Run %s", EscapeCommandData(title))
 
 	if len(step.With) > 0 {
 		rawLogger.Infof("with:")
 		for _, k := range slices.Sorted(maps.Keys(step.With)) {
-			rawLogger.Infof("  %s: %s", k, step.With[k])
+			logKeyedValue(rawLogger, k, step.With[k])
 		}
 	}
 
@@ -129,7 +130,17 @@ func printStepEnvBlock(ctx context.Context, step *model.Step, env map[string]str
 		if caseInsensitive {
 			lookupKey = strings.ToUpper(k)
 		}
-		rawLogger.Infof("  %s: %s", k, envLookup[lookupKey])
+		logKeyedValue(rawLogger, k, envLookup[lookupKey])
+	}
+}
+
+// logKeyedValue prints one row per line of value: Gitea stores one log row per line, so an
+// embedded newline would reach the user as a literal "\n".
+func logKeyedValue(rawLogger *logrus.Entry, key, value string) {
+	lines := strings.Split(strings.ReplaceAll(value, "\r\n", "\n"), "\n")
+	rawLogger.Infof("  %s: %s", key, lines[0])
+	for _, line := range lines[1:] {
+		rawLogger.Infof("    %s", line)
 	}
 }
 

act/runner/step_test.go

@@ -6,6 +6,7 @@ package runner
 
 import (
 	"context"
+	"errors"
 	"testing"
 
 	"gitea.com/gitea/runner/act/common"
@@ -14,6 +15,7 @@ import (
 	log "github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
 	yaml "go.yaml.in/yaml/v4"
 )
 
@@ -354,3 +356,48 @@ func TestIsContinueOnError(t *testing.T) {
 	assertObject.False(continueOnError)
 	assertObject.Error(err)
 }
+
+// A refused ::set-env::/::add-path:: records a job-scoped error. When the step that
+// produced it also fails on its own, the refusal must be cleared at the step boundary, so
+// it fails only that step and never leaks onto a later step that runs anyway (if: always()).
+func TestRunStepExecutorDoesNotLeakRefusalToNextStep(t *testing.T) {
+	cm := &containerMock{}
+	noop := func(context.Context) error { return nil }
+	cm.On("Copy", mock.Anything, mock.Anything).Return(noop)
+	cm.On("UpdateFromEnv", mock.Anything, mock.Anything).Return(noop)
+
+	rc := &RunContext{
+		Config: &Config{Env: map[string]string{}},
+		Run: &model.Run{
+			JobID:    "1",
+			Workflow: &model.Workflow{Jobs: map[string]*model.Job{"1": {}}},
+		},
+		Env:          map[string]string{},
+		StepResults:  map[string]*model.StepResult{},
+		JobContainer: cm,
+	}
+	rc.ExprEval = rc.NewExpressionEvaluator(context.Background())
+	// Dryrun skips reading the path file back from the (mocked) container.
+	ctx := common.WithDryrun(context.Background(), true)
+
+	// A refusal parsed out of the job container's own output belongs to no step, so the
+	// first step must not be failed by it.
+	rc.commandHandler(ctx)("::set-env name=setup::y\n")
+	stepSetup := &stepRun{RunContext: rc, Step: &model.Step{ID: "setup"}, env: map[string]string{}}
+	require.NoError(t, runStepExecutor(stepSetup, stepStageMain, func(context.Context) error { return nil })(ctx))
+
+	// Step A refuses a ::set-env:: and then fails on its own.
+	stepA := &stepRun{RunContext: rc, Step: &model.Step{ID: "a"}, env: map[string]string{}}
+	errA := runStepExecutor(stepA, stepStageMain, func(context.Context) error {
+		rc.commandHandler(ctx)("::set-env name=x::y\n")
+		return errors.New("boom")
+	})(ctx)
+	// The step fails with its own error, not the refusal.
+	require.ErrorContains(t, errA, "boom")
+
+	// Step B runs despite step A's failure (if: always()) and issues no unsecure command;
+	// it must not inherit step A's refusal.
+	stepB := &stepRun{RunContext: rc, Step: &model.Step{ID: "b", If: yaml.Node{Value: "always()"}}, env: map[string]string{}}
+	errB := runStepExecutor(stepB, stepStageMain, func(context.Context) error { return nil })(ctx)
+	require.NoError(t, errB)
+}

act/runner/testdata/GITHUB_ENV-use-in-env-ctx/push.yml

@@ -3,6 +3,7 @@ jobs:
   _:
     runs-on: ubuntu-latest
     env:
+      ACTIONS_ALLOW_UNSECURE_COMMANDS: 'true'
       MYGLOBALENV3: myglobalval3
     steps:
     - uses: actions/checkout@v4

act/runner/testdata/commands/push.yml

@@ -4,6 +4,8 @@ on: push
 jobs:
   build:
     runs-on: ubuntu-latest
+    env:
+      ACTIONS_ALLOW_UNSECURE_COMMANDS: 'true'
     steps:
       - name: TEST set-env
         run: echo "::set-env name=foo::bar"