Merge pull request #333 from pgsty/claude/cross-bucket-path-traversal-delete-5e1fc2

fix(pools): keep rejected names out of a single-pool bulk delete

CHANGELOG.md

@@ -20,6 +20,17 @@
   `svcacct info` reports with `Policy: implied`, and set the policy again on
   those that were meant to be restricted.
 
+- S3 `DeleteObjects` on a single pool stops at an entry whose name fails the
+  object name check: the entry returns `XMinioInvalidObjectName` and is not
+  locked or sent to a drive, as with a single-object DELETE and with more than
+  one pool. Until now such an entry still reached the drives of the node, where
+  a name with a `..` segment was joined to the request bucket. A caller allowed
+  to delete in one bucket could remove a version in another bucket, including
+  one under Object Lock retention, and from a versioned bucket could put a
+  delete marker on an object of another bucket or on stored system metadata
+  such as a bucket's configuration. The other entries of a request are deleted
+  as before.
+
 ## RELEASE.2026-11-09T00-00-00Z
 
 Package version: `20261109000000.0.0`. Publication status and artifacts are

cmd/bulk-delete-invalid-name_test.go

@@ -0,0 +1,156 @@
+// Copyright (c) 2026 PGSTY
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+package cmd
+
+import (
+	"bytes"
+	"encoding/xml"
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"testing"
+
+	"github.com/minio/minio/internal/auth"
+)
+
+// A bulk delete joins each name to the request bucket on the drives, so a name
+// with a ".." segment names a path in another bucket or in the meta bucket.
+// Such a name is the error of its own entry and reaches no drive, and the
+// other entries of the request are deleted as usual. This holds for the one
+// bulk lock of a single node, for a pool that locks per set, and for more than
+// one pool.
+func TestPoolsBulkDeleteInvalidNames(t *testing.T) {
+	for _, topology := range []struct {
+		name string
+		new  func(t *testing.T) (*erasureServerPools, string)
+	}{
+		{"single node", func(t *testing.T) (*erasureServerPools, string) { return bulkDeletePools(t, 1) }},
+		{"set locks", func(t *testing.T) (*erasureServerPools, string) { return ldPool(t, ldLocal) }},
+		{"two pools", func(t *testing.T) (*erasureServerPools, string) { return bulkDeletePools(t, 2) }},
+	} {
+		t.Run(topology.name, func(t *testing.T) {
+			z, bucket := topology.new(t)
+			ctx := t.Context()
+			other := "bulk-delete-other"
+			if err := z.MakeBucket(ctx, other, MakeBucketOptions{VersioningEnabled: true}); err != nil {
+				t.Fatal(err)
+			}
+			old := batchPutVersion(t, z, other, "kept", nil)
+			latest := batchPutVersion(t, z, other, "kept", nil)
+			batchPutVersion(t, z, other, "visible", nil)
+			metaKey := pathJoin(bucketMetaPrefix, other, bucketMetadataFile)
+			if !batchVersionExists(t, z, minioMetaBucket, metaKey, "") {
+				t.Fatal("the bucket metadata is not an object of the meta bucket")
+			}
+			for _, key := range []string{"own", "dir/"} {
+				if _, err := z.PutObject(ctx, bucket, key, mustGetPutObjReader(t, bytes.NewReader(nil), 0, "", ""), ObjectOptions{}); err != nil {
+					t.Fatal(err)
+				}
+			}
+
+			names := []ObjectToDelete{
+				{ObjectV: ObjectV{ObjectName: "../" + other + "/kept", VersionID: old.VersionID}}, // purge in another bucket
+				{ObjectV: ObjectV{ObjectName: "own"}},
+				{ObjectV: ObjectV{ObjectName: "a/../../" + other + "/visible"}},         // marker in another bucket
+				{ObjectV: ObjectV{ObjectName: "../" + minioMetaBucket + "/" + metaKey}}, // marker on bucket metadata
+				{ObjectV: ObjectV{ObjectName: "dir/"}},
+				{ObjectV: ObjectV{ObjectName: ""}},
+			}
+			invalid := map[int]bool{0: true, 2: true, 3: true, 5: true}
+			// Without a version ID these options ask for a delete marker, the
+			// one write a bulk delete makes.
+			deleted, errs := z.DeleteObjects(ctx, bucket, slices.Clone(names), ObjectOptions{Versioned: true})
+			for i, name := range names {
+				_, rejected := errs[i].(ObjectNameInvalid)
+				if rejected != invalid[i] || !invalid[i] && errs[i] != nil {
+					t.Errorf("%d %q: error = %v, rejected as invalid = %v, want %v", i, name.ObjectName, errs[i], rejected, invalid[i])
+				}
+				if deleted[i].ObjectName != name.ObjectName || deleted[i].found == invalid[i] {
+					t.Errorf("%d %q: result = %+v", i, name.ObjectName, deleted[i])
+				}
+			}
+
+			for _, version := range []string{old.VersionID, latest.VersionID} {
+				if !batchVersionExists(t, z, other, "kept", version) {
+					t.Errorf("version %q of the object in the other bucket was removed", version)
+				}
+			}
+			if !batchVersionExists(t, z, other, "visible", "") {
+				t.Error("the object of the other bucket is hidden by a marker")
+			}
+			if !batchVersionExists(t, z, minioMetaBucket, metaKey, "") {
+				t.Error("the metadata of the other bucket is hidden by a marker")
+			}
+			for _, key := range []string{"own", "dir/"} {
+				if batchVersionExists(t, z, bucket, key, "") {
+					t.Errorf("%q of the request bucket was not deleted", key)
+				}
+			}
+		})
+	}
+}
+
+// The names of an S3 DeleteObjects request come from its body, which the path
+// checks of the request URL do not see. A user allowed to delete in one bucket
+// reaches nothing outside it through such a name: a version under COMPLIANCE
+// retention in another bucket stays, and no delete marker lands on that object
+// or on the stored metadata of its bucket.
+func TestBulkDeleteObjectLockNameOutsideBucket(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t: t, endpoints: []string{"DeleteMultipleObjects"},
+		makeBucketOptions: MakeBucketOptions{VersioningEnabled: true},
+		objAPITest: func(obj ObjectLayer, instance, bucket string, router http.Handler, _ auth.Credentials, t *testing.T) {
+			ctx := t.Context()
+			user := newObjectAttributesAuthzUser(t, instance, bucket, `"s3:DeleteObject","s3:DeleteObjectVersion"`)
+			locked := getRandomBucketName()
+			if err := obj.MakeBucket(ctx, locked, MakeBucketOptions{VersioningEnabled: true, LockEnabled: true}); err != nil {
+				t.Fatal(err)
+			}
+			enableBucketObjectLock(t, locked)
+			worm := batchPutVersion(t, obj, locked, "secret", batchLockMeta("COMPLIANCE"))
+			batchPutVersion(t, obj, bucket, "own", nil)
+			metaKey := pathJoin(bucketMetaPrefix, locked, bucketMetadataFile)
+
+			outside := []ObjectToDelete{
+				{ObjectV: ObjectV{ObjectName: "../" + locked + "/secret", VersionID: worm.VersionID}},
+				{ObjectV: ObjectV{ObjectName: "../" + locked + "/secret"}},
+				{ObjectV: ObjectV{ObjectName: "../" + minioMetaBucket + "/" + metaKey}},
+			}
+			body := encodeResponse(DeleteObjectsRequest{Objects: append(slices.Clone(outside), ObjectToDelete{ObjectV: ObjectV{ObjectName: "own"}})})
+			req, err := newTestSignedRequestV4(http.MethodPost, getDeleteMultipleObjectsURL("", bucket), int64(len(body)), bytes.NewReader(body),
+				user.AccessKey, user.SecretKey, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			rec := httptest.NewRecorder()
+			router.ServeHTTP(rec, req)
+			var resp DeleteObjectsResponse
+			if rec.Code != http.StatusOK || xml.Unmarshal(rec.Body.Bytes(), &resp) != nil {
+				t.Fatalf("%s: status %d: %s", instance, rec.Code, rec.Body.String())
+			}
+
+			if len(resp.DeletedObjects) != 1 || resp.DeletedObjects[0].ObjectName != "own" || len(resp.Errors) != len(outside) {
+				t.Errorf("%s: want the three names outside the bucket refused and \"own\" deleted: %s", instance, rec.Body.String())
+			}
+			for _, e := range resp.Errors {
+				if e.Code != errorCodes[ErrInvalidObjectName].Code {
+					t.Errorf("%s: %q: code %s, want %s", instance, e.Key, e.Code, errorCodes[ErrInvalidObjectName].Code)
+				}
+			}
+			if !batchVersionExists(t, obj, locked, "secret", worm.VersionID) {
+				t.Errorf("%s: the version under COMPLIANCE retention in the other bucket was removed", instance)
+			}
+			if !batchVersionExists(t, obj, locked, "secret", "") {
+				t.Errorf("%s: a delete marker hides the object of the other bucket", instance)
+			}
+			if !batchVersionExists(t, obj, minioMetaBucket, metaKey, "") {
+				t.Errorf("%s: a delete marker hides the stored metadata of the other bucket", instance)
+			}
+			if batchVersionExists(t, obj, bucket, "own", "") {
+				t.Errorf("%s: the object of the request bucket was not deleted", instance)
+			}
+		},
+	})
+}

cmd/erasure-server-pool.go

@@ -26,6 +26,7 @@ import (
 	"math/rand"
 	"net/http"
 	"path"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -1543,6 +1544,27 @@ func (z *erasureServerPools) DeleteObjects(ctx context.Context, bucket string, o
 		objSets.Add(objects[i].ObjectName)
 	}
 
+	// A name that fails the check keeps its error and goes no further. Joined
+	// to the bucket it can name a path in another bucket or in the meta
+	// bucket, so it is not locked, looked up or sent to a drive. The other
+	// names are deleted as a request of their own: everything below sees only
+	// names that passed.
+	if slices.ContainsFunc(derrs, func(err error) bool { return err != nil }) {
+		valid, at := make([]ObjectToDelete, 0, len(objects)), make([]int, 0, len(objects))
+		for i, obj := range objects {
+			if derrs[i] == nil {
+				valid, at = append(valid, obj), append(at, i)
+			}
+		}
+		if len(valid) > 0 {
+			deleted, errs := z.DeleteObjects(ctx, bucket, valid, opts)
+			for j, i := range at {
+				dobjects[i], derrs[i] = deleted[j], errs[j]
+			}
+		}
+		return dobjects, derrs
+	}
+
 	// A single pool locks each name in the set its writers lock it in, one
 	// set at a time. A single node keeps one lock table for all sets, so it
 	// keeps the one bulk lock below: its local lock takes the names one by