Fix faulty handling of named pipes; closes pterodactyl/panel#4059

router/router_server_files.go

@@ -37,6 +37,15 @@ func getServerFileContents(c *gin.Context) {
 		return
 	}
 	defer f.Close()
+	// Don't allow a named pipe to be opened.
+	//
+	// @see https://github.com/pterodactyl/panel/issues/4059
+	if st.Mode()&os.ModeNamedPipe != 0 {
+		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
+			"error": "Cannot open files of this type.",
+		})
+		return
+	}
 
 	c.Header("X-Mime-Type", st.Mimetype)
 	c.Header("Content-Length", strconv.Itoa(int(st.Size())))

server/filesystem/filesystem.go

@@ -115,19 +115,6 @@ func (fs *Filesystem) Touch(p string, flag int) (*os.File, error) {
 	return f, nil
 }
 
-// Reads a file on the system and returns it as a byte representation in a file
-// reader. This is not the most memory efficient usage since it will be reading the
-// entirety of the file into memory.
-func (fs *Filesystem) Readfile(p string, w io.Writer) error {
-	file, _, err := fs.File(p)
-	if err != nil {
-		return err
-	}
-	defer file.Close()
-	_, err = bufio.NewReader(file).WriteTo(w)
-	return err
-}
-
 // Writefile writes a file to the system. If the file does not already exist one
 // will be created. This will also properly recalculate the disk space used by
 // the server when writing new files or modifying existing ones.
@@ -492,7 +479,11 @@ func (fs *Filesystem) ListDirectory(p string) ([]Stat, error) {
 					cleanedp, _ = fs.SafePath(filepath.Join(cleaned, f.Name()))
 				}
 
-				if cleanedp != "" {
+				// Don't try to detect the type on a pipe — this will just hang the application and
+				// you'll never get a response back.
+				//
+				// @see https://github.com/pterodactyl/panel/issues/4059
+				if cleanedp != "" && f.Mode()&os.ModeNamedPipe == 0 {
 					m, _ = mimetype.DetectFile(filepath.Join(cleaned, f.Name()))
 				} else {
 					// Just pass this for an unknown type because the file could not safely be resolved within

server/filesystem/filesystem_test.go

@@ -1,6 +1,7 @@
 package filesystem
 
 import (
+	"bufio"
 	"bytes"
 	"errors"
 	"math/rand"
@@ -44,6 +45,14 @@ type rootFs struct {
 	root string
 }
 
+func getFileContent(file *os.File) string {
+	var w bytes.Buffer
+	if _, err := bufio.NewReader(file).WriteTo(&w); err != nil {
+		panic(err)
+	}
+	return w.String()
+}
+
 func (rfs *rootFs) CreateServerFile(p string, c []byte) error {
 	f, err := os.Create(filepath.Join(rfs.root, "/server", p))
 
@@ -75,54 +84,6 @@ func (rfs *rootFs) reset() {
 	}
 }
 
-func TestFilesystem_Readfile(t *testing.T) {
-	g := Goblin(t)
-	fs, rfs := NewFs()
-
-	g.Describe("Readfile", func() {
-		buf := &bytes.Buffer{}
-
-		g.It("opens a file if it exists on the system", func() {
-			err := rfs.CreateServerFileFromString("test.txt", "testing")
-			g.Assert(err).IsNil()
-
-			err = fs.Readfile("test.txt", buf)
-			g.Assert(err).IsNil()
-			g.Assert(buf.String()).Equal("testing")
-		})
-
-		g.It("returns an error if the file does not exist", func() {
-			err := fs.Readfile("test.txt", buf)
-			g.Assert(err).IsNotNil()
-			g.Assert(errors.Is(err, os.ErrNotExist)).IsTrue()
-		})
-
-		g.It("returns an error if the \"file\" is a directory", func() {
-			err := os.Mkdir(filepath.Join(rfs.root, "/server/test.txt"), 0o755)
-			g.Assert(err).IsNil()
-
-			err = fs.Readfile("test.txt", buf)
-			g.Assert(err).IsNotNil()
-			g.Assert(IsErrorCode(err, ErrCodeIsDirectory)).IsTrue()
-		})
-
-		g.It("cannot open a file outside the root directory", func() {
-			err := rfs.CreateServerFileFromString("/../test.txt", "testing")
-			g.Assert(err).IsNil()
-
-			err = fs.Readfile("/../test.txt", buf)
-			g.Assert(err).IsNotNil()
-			g.Assert(IsErrorCode(err, ErrCodePathResolution)).IsTrue()
-		})
-
-		g.AfterEach(func() {
-			buf.Truncate(0)
-			atomic.StoreInt64(&fs.diskUsed, 0)
-			rfs.reset()
-		})
-	})
-}
-
 func TestFilesystem_Writefile(t *testing.T) {
 	g := Goblin(t)
 	fs, rfs := NewFs()
@@ -140,9 +101,10 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err := fs.Writefile("test.txt", r)
 			g.Assert(err).IsNil()
 
-			err = fs.Readfile("test.txt", buf)
+			f, _, err := fs.File("test.txt")
 			g.Assert(err).IsNil()
-			g.Assert(buf.String()).Equal("test file content")
+			defer f.Close()
+			g.Assert(getFileContent(f)).Equal("test file content")
 			g.Assert(atomic.LoadInt64(&fs.diskUsed)).Equal(r.Size())
 		})
 
@@ -152,9 +114,10 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err := fs.Writefile("/some/nested/test.txt", r)
 			g.Assert(err).IsNil()
 
-			err = fs.Readfile("/some/nested/test.txt", buf)
+			f, _, err := fs.File("/some/nested/test.txt")
 			g.Assert(err).IsNil()
-			g.Assert(buf.String()).Equal("test file content")
+			defer f.Close()
+			g.Assert(getFileContent(f)).Equal("test file content")
 		})
 
 		g.It("can create a new file inside a nested directory without a trailing slash", func() {
@@ -163,9 +126,10 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err := fs.Writefile("some/../foo/bar/test.txt", r)
 			g.Assert(err).IsNil()
 
-			err = fs.Readfile("foo/bar/test.txt", buf)
+			f, _, err := fs.File("foo/bar/test.txt")
 			g.Assert(err).IsNil()
-			g.Assert(buf.String()).Equal("test file content")
+			defer f.Close()
+			g.Assert(getFileContent(f)).Equal("test file content")
 		})
 
 		g.It("cannot create a file outside the root directory", func() {
@@ -190,28 +154,6 @@ func TestFilesystem_Writefile(t *testing.T) {
 			g.Assert(IsErrorCode(err, ErrCodeDiskSpace)).IsTrue()
 		})
 
-		/*g.It("updates the total space used when a file is appended to", func() {
-			atomic.StoreInt64(&fs.diskUsed, 100)
-
-			b := make([]byte, 100)
-			_, _ = rand.Read(b)
-
-			r := bytes.NewReader(b)
-			err := fs.Writefile("test.txt", r)
-			g.Assert(err).IsNil()
-			g.Assert(atomic.LoadInt64(&fs.diskUsed)).Equal(int64(200))
-
-			// If we write less data than already exists, we should expect the total
-			// disk used to be decremented.
-			b = make([]byte, 50)
-			_, _ = rand.Read(b)
-
-			r = bytes.NewReader(b)
-			err = fs.Writefile("test.txt", r)
-			g.Assert(err).IsNil()
-			g.Assert(atomic.LoadInt64(&fs.diskUsed)).Equal(int64(150))
-		})*/
-
 		g.It("truncates the file when writing new contents", func() {
 			r := bytes.NewReader([]byte("original data"))
 			err := fs.Writefile("test.txt", r)
@@ -221,9 +163,10 @@ func TestFilesystem_Writefile(t *testing.T) {
 			err = fs.Writefile("test.txt", r)
 			g.Assert(err).IsNil()
 
-			err = fs.Readfile("test.txt", buf)
+			f, _, err := fs.File("test.txt")
 			g.Assert(err).IsNil()
-			g.Assert(buf.String()).Equal("new data")
+			defer f.Close()
+			g.Assert(getFileContent(f)).Equal("new data")
 		})
 
 		g.AfterEach(func() {

server/filesystem/path_test.go

@@ -119,16 +119,6 @@ func TestFilesystem_Blocks_Symlinks(t *testing.T) {
 		panic(err)
 	}
 
-	g.Describe("Readfile", func() {
-		g.It("cannot read a file symlinked outside the root", func() {
-			b := bytes.Buffer{}
-
-			err := fs.Readfile("symlinked.txt", &b)
-			g.Assert(err).IsNotNil()
-			g.Assert(IsErrorCode(err, ErrCodePathResolution)).IsTrue()
-		})
-	})
-
 	g.Describe("Writefile", func() {
 		g.It("cannot write to a file symlinked outside the root", func() {
 			r := bytes.NewReader([]byte("testing"))