From eeeaa639233fcebd67409b692e462c659c5869e0 Mon Sep 17 00:00:00 2001
From: Andrei Vagin <avagin@gmail.com>
Date: Fri, 3 Dec 2021 15:34:41 -0800
Subject: [PATCH] vfs: Don't allow to splice in all file descriptors

We want to avoid unneeded side effects, so let's specify what file descriptors
allow to splice data in. Linux does the same thing.

For example, Splicing a big amout of data to eventfd can be slow, because
eventfd can consume only 8 bytes at once.

Reported-by: syzbot+b9610cff22c10d9bead4@syzkaller.appspotmail.com
---
 pkg/sentry/devices/memdev/full.go             |  1 +
 pkg/sentry/devices/memdev/null.go             |  1 +
 pkg/sentry/devices/memdev/random.go           |  1 +
 pkg/sentry/devices/memdev/zero.go             |  1 +
 pkg/sentry/devices/tundev/tundev.go           |  1 +
 pkg/sentry/fsimpl/devpts/master.go            |  1 +
 pkg/sentry/fsimpl/devpts/replica.go           |  1 +
 pkg/sentry/fsimpl/eventfd/eventfd.go          |  1 +
 pkg/sentry/fsimpl/fuse/dev.go                 |  1 +
 pkg/sentry/fsimpl/fuse/directory.go           |  1 +
 pkg/sentry/fsimpl/fuse/regular_file.go        |  1 +
 pkg/sentry/fsimpl/gofer/gofer.go              |  1 +
 pkg/sentry/fsimpl/gofer/regular_file.go       |  1 +
 pkg/sentry/fsimpl/host/host.go                |  1 +
 .../fsimpl/kernfs/dynamic_bytes_file.go       |  1 +
 pkg/sentry/fsimpl/mqfs/queue.go               |  1 +
 pkg/sentry/fsimpl/overlay/regular_file.go     |  1 +
 pkg/sentry/fsimpl/proc/task_files.go          |  3 +++
 pkg/sentry/fsimpl/signalfd/signalfd.go        |  1 +
 pkg/sentry/fsimpl/sys/kcov.go                 |  1 +
 pkg/sentry/fsimpl/timerfd/timerfd.go          |  1 +
 pkg/sentry/fsimpl/tmpfs/regular_file.go       |  1 +
 pkg/sentry/fsimpl/verity/verity.go            |  1 +
 pkg/sentry/kernel/pipe/vfs.go                 |  1 +
 pkg/sentry/socket/hostinet/socket_vfs2.go     |  1 +
 pkg/sentry/socket/netlink/socket_vfs2.go      |  1 +
 pkg/sentry/socket/netstack/netstack_vfs2.go   |  1 +
 pkg/sentry/socket/unix/unix_vfs2.go           |  1 +
 pkg/sentry/syscalls/linux/vfs2/splice.go      |  9 +++++++
 pkg/sentry/vfs/epoll.go                       |  1 +
 pkg/sentry/vfs/file_description.go            |  3 +++
 pkg/sentry/vfs/file_description_impl_util.go  | 27 +++++++++++++++++++
 .../vfs/file_description_impl_util_test.go    |  1 +
 pkg/sentry/vfs/inotify.go                     |  1 +
 pkg/sentry/vfs/opath.go                       |  1 +
 35 files changed, 73 insertions(+)

diff --git a/pkg/sentry/devices/memdev/full.go b/pkg/sentry/devices/memdev/full.go
index fc702c9f6..d7cfa599c 100644
--- a/pkg/sentry/devices/memdev/full.go
+++ b/pkg/sentry/devices/memdev/full.go
@@ -47,6 +47,7 @@ type fullFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
diff --git a/pkg/sentry/devices/memdev/null.go b/pkg/sentry/devices/memdev/null.go
index ff5837747..a55c06633 100644
--- a/pkg/sentry/devices/memdev/null.go
+++ b/pkg/sentry/devices/memdev/null.go
@@ -48,6 +48,7 @@ type nullFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
diff --git a/pkg/sentry/devices/memdev/random.go b/pkg/sentry/devices/memdev/random.go
index ac943e3ba..0c7ef6aec 100644
--- a/pkg/sentry/devices/memdev/random.go
+++ b/pkg/sentry/devices/memdev/random.go
@@ -53,6 +53,7 @@ type randomFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 
 	// off is the "file offset". off is accessed using atomic memory
 	// operations.
diff --git a/pkg/sentry/devices/memdev/zero.go b/pkg/sentry/devices/memdev/zero.go
index 49c53452a..cb46266c6 100644
--- a/pkg/sentry/devices/memdev/zero.go
+++ b/pkg/sentry/devices/memdev/zero.go
@@ -50,6 +50,7 @@ type zeroFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 }
 
 // Release implements vfs.FileDescriptionImpl.Release.
diff --git a/pkg/sentry/devices/tundev/tundev.go b/pkg/sentry/devices/tundev/tundev.go
index c98c8d3f8..2fb2a029d 100644
--- a/pkg/sentry/devices/tundev/tundev.go
+++ b/pkg/sentry/devices/tundev/tundev.go
@@ -60,6 +60,7 @@ type tunFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 
 	device tun.Device
 }
diff --git a/pkg/sentry/fsimpl/devpts/master.go b/pkg/sentry/fsimpl/devpts/master.go
index 35a682b40..17ab4b122 100644
--- a/pkg/sentry/fsimpl/devpts/master.go
+++ b/pkg/sentry/fsimpl/devpts/master.go
@@ -90,6 +90,7 @@ type masterFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.NoSpliceInFD
 
 	inode *masterInode
 	t     *Terminal
diff --git a/pkg/sentry/fsimpl/devpts/replica.go b/pkg/sentry/fsimpl/devpts/replica.go
index eced9e618..5235d7cbe 100644
--- a/pkg/sentry/fsimpl/devpts/replica.go
+++ b/pkg/sentry/fsimpl/devpts/replica.go
@@ -102,6 +102,7 @@ type replicaFileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.NoSpliceInFD
 
 	inode *replicaInode
 }
diff --git a/pkg/sentry/fsimpl/eventfd/eventfd.go b/pkg/sentry/fsimpl/eventfd/eventfd.go
index f79d2b252..49d93eb1d 100644
--- a/pkg/sentry/fsimpl/eventfd/eventfd.go
+++ b/pkg/sentry/fsimpl/eventfd/eventfd.go
@@ -42,6 +42,7 @@ type EventFileDescription struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.NoSpliceInFD
 
 	// queue is used to notify interested parties when the event object
 	// becomes readable or writable.
diff --git a/pkg/sentry/fsimpl/fuse/dev.go b/pkg/sentry/fsimpl/fuse/dev.go
index 55d86b933..77483e902 100644
--- a/pkg/sentry/fsimpl/fuse/dev.go
+++ b/pkg/sentry/fsimpl/fuse/dev.go
@@ -57,6 +57,7 @@ type DeviceFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 
 	// nextOpID is used to create new requests.
 	nextOpID linux.FUSEOpID
diff --git a/pkg/sentry/fsimpl/fuse/directory.go b/pkg/sentry/fsimpl/fuse/directory.go
index 9611edd5a..880466434 100644
--- a/pkg/sentry/fsimpl/fuse/directory.go
+++ b/pkg/sentry/fsimpl/fuse/directory.go
@@ -28,6 +28,7 @@ import (
 
 type directoryFD struct {
 	fileDescription
+	vfs.NoSpliceInFD
 }
 
 // Allocate implements directoryFD.Allocate.
diff --git a/pkg/sentry/fsimpl/fuse/regular_file.go b/pkg/sentry/fsimpl/fuse/regular_file.go
index 38cde8208..c2270df5d 100644
--- a/pkg/sentry/fsimpl/fuse/regular_file.go
+++ b/pkg/sentry/fsimpl/fuse/regular_file.go
@@ -29,6 +29,7 @@ import (
 
 type regularFileFD struct {
 	fileDescription
+	vfs.SpliceInFD
 
 	// off is the file offset.
 	off int64
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 5ef3cf445..a6039d103 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -2443,6 +2443,7 @@ type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	lockLogging sync.Once `state:"nosave"`
 }
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go
index 874f9873d..d48b4200f 100644
--- a/pkg/sentry/fsimpl/gofer/regular_file.go
+++ b/pkg/sentry/fsimpl/gofer/regular_file.go
@@ -45,6 +45,7 @@ func (d *dentry) isRegularFile() bool {
 // +stateify savable
 type regularFileFD struct {
 	fileDescription
+	vfs.SpliceInFD
 
 	// off is the file offset. off is protected by mu.
 	mu  sync.Mutex `state:"nosave"`
diff --git a/pkg/sentry/fsimpl/host/host.go b/pkg/sentry/fsimpl/host/host.go
index c4e58f82c..b469b35d1 100644
--- a/pkg/sentry/fsimpl/host/host.go
+++ b/pkg/sentry/fsimpl/host/host.go
@@ -649,6 +649,7 @@ type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	// inode is vfsfd.Dentry().Impl().(*kernfs.Dentry).Inode().(*inode), but
 	// cached to reduce indirections and casting. fileDescription does not hold
diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
index 652ade564..59871d880 100644
--- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
+++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
@@ -89,6 +89,7 @@ type DynamicBytesFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DynamicBytesFileDescriptionImpl
 	vfs.LockFD
+	vfs.NoSpliceInFD
 
 	vfsfd vfs.FileDescription
 	inode Inode
diff --git a/pkg/sentry/fsimpl/mqfs/queue.go b/pkg/sentry/fsimpl/mqfs/queue.go
index eee2bd8f6..8cfbdd9c4 100644
--- a/pkg/sentry/fsimpl/mqfs/queue.go
+++ b/pkg/sentry/fsimpl/mqfs/queue.go
@@ -61,6 +61,7 @@ type queueFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DynamicBytesFileDescriptionImpl
 	vfs.LockFD
+	vfs.NoSpliceInFD
 
 	vfsfd vfs.FileDescription
 	inode kernfs.Inode
diff --git a/pkg/sentry/fsimpl/overlay/regular_file.go b/pkg/sentry/fsimpl/overlay/regular_file.go
index 65d270c69..42ec73165 100644
--- a/pkg/sentry/fsimpl/overlay/regular_file.go
+++ b/pkg/sentry/fsimpl/overlay/regular_file.go
@@ -50,6 +50,7 @@ func (d *dentry) readlink(ctx context.Context) (string, error) {
 // +stateify savable
 type regularFileFD struct {
 	fileDescription
+	vfs.SpliceInFD
 
 	// If copiedUp is false, cachedFD represents
 	// fileDescription.dentry().lowerVDs[0]; otherwise, cachedFD represents
diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go
index d3f9cf489..9936a1e29 100644
--- a/pkg/sentry/fsimpl/proc/task_files.go
+++ b/pkg/sentry/fsimpl/proc/task_files.go
@@ -434,6 +434,7 @@ type memFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	inode *memInode
 
@@ -678,6 +679,7 @@ type statusFD struct {
 	statusFDLowerBase
 	vfs.DynamicBytesFileDescriptionImpl
 	vfs.LockFD
+	vfs.NoSpliceInFD
 
 	vfsfd vfs.FileDescription
 
@@ -1173,6 +1175,7 @@ func (i *namespaceInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *ker
 type namespaceFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.NoSpliceInFD
 
 	vfsfd vfs.FileDescription
 	inode *namespaceInode
diff --git a/pkg/sentry/fsimpl/signalfd/signalfd.go b/pkg/sentry/fsimpl/signalfd/signalfd.go
index a1f8aed14..129748acf 100644
--- a/pkg/sentry/fsimpl/signalfd/signalfd.go
+++ b/pkg/sentry/fsimpl/signalfd/signalfd.go
@@ -34,6 +34,7 @@ type SignalFileDescription struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.NoSpliceInFD
 
 	// target is the original signal target task.
 	//
diff --git a/pkg/sentry/fsimpl/sys/kcov.go b/pkg/sentry/fsimpl/sys/kcov.go
index 51f0bf3d8..06efa4cb5 100644
--- a/pkg/sentry/fsimpl/sys/kcov.go
+++ b/pkg/sentry/fsimpl/sys/kcov.go
@@ -67,6 +67,7 @@ func (i *kcovInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.D
 type kcovFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.NoLockFD
+	vfs.SpliceInFD
 
 	vfsfd vfs.FileDescription
 	inode *kcovInode
diff --git a/pkg/sentry/fsimpl/timerfd/timerfd.go b/pkg/sentry/fsimpl/timerfd/timerfd.go
index 467c76596..94f4e39ef 100644
--- a/pkg/sentry/fsimpl/timerfd/timerfd.go
+++ b/pkg/sentry/fsimpl/timerfd/timerfd.go
@@ -36,6 +36,7 @@ type TimerFileDescription struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.NoLockFD
+	vfs.NoSpliceInFD
 
 	events waiter.Queue
 	timer  *ktime.Timer
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index 3a30e043f..439c57af8 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -332,6 +332,7 @@ func (*regularFile) InvalidateUnsavable(context.Context) error {
 // +stateify savable
 type regularFileFD struct {
 	fileDescription
+	vfs.SpliceInFD
 
 	// off is the file offset. off is accessed using atomic memory operations.
 	// offMu serializes operations that may mutate off.
diff --git a/pkg/sentry/fsimpl/verity/verity.go b/pkg/sentry/fsimpl/verity/verity.go
index d2526263c..d144b8921 100644
--- a/pkg/sentry/fsimpl/verity/verity.go
+++ b/pkg/sentry/fsimpl/verity/verity.go
@@ -989,6 +989,7 @@ func (d *dentry) readlink(ctx context.Context) (string, error) {
 type fileDescription struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
+	vfs.NoSpliceInFD
 
 	// d is the corresponding dentry to the fileDescription.
 	d *dentry
diff --git a/pkg/sentry/kernel/pipe/vfs.go b/pkg/sentry/kernel/pipe/vfs.go
index a3011bacf..bb6f8f84d 100644
--- a/pkg/sentry/kernel/pipe/vfs.go
+++ b/pkg/sentry/kernel/pipe/vfs.go
@@ -186,6 +186,7 @@ type VFSPipeFD struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	pipe *Pipe
 }
diff --git a/pkg/sentry/socket/hostinet/socket_vfs2.go b/pkg/sentry/socket/hostinet/socket_vfs2.go
index 5bea70106..d7bc899fe 100644
--- a/pkg/sentry/socket/hostinet/socket_vfs2.go
+++ b/pkg/sentry/socket/hostinet/socket_vfs2.go
@@ -36,6 +36,7 @@ type socketVFS2 struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	// We store metadata for hostinet sockets internally. Technically, we should
 	// access metadata (e.g. through stat, chmod) on the host for correctness,
diff --git a/pkg/sentry/socket/netlink/socket_vfs2.go b/pkg/sentry/socket/netlink/socket_vfs2.go
index 0de568e5a..ee4dd93f2 100644
--- a/pkg/sentry/socket/netlink/socket_vfs2.go
+++ b/pkg/sentry/socket/netlink/socket_vfs2.go
@@ -43,6 +43,7 @@ type SocketVFS2 struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	socketOpsCommon
 }
diff --git a/pkg/sentry/socket/netstack/netstack_vfs2.go b/pkg/sentry/socket/netstack/netstack_vfs2.go
index 145951145..0cfc5bfcf 100644
--- a/pkg/sentry/socket/netstack/netstack_vfs2.go
+++ b/pkg/sentry/socket/netstack/netstack_vfs2.go
@@ -41,6 +41,7 @@ type SocketVFS2 struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	socketOpsCommon
 }
diff --git a/pkg/sentry/socket/unix/unix_vfs2.go b/pkg/sentry/socket/unix/unix_vfs2.go
index fd1194bc1..f110a0103 100644
--- a/pkg/sentry/socket/unix/unix_vfs2.go
+++ b/pkg/sentry/socket/unix/unix_vfs2.go
@@ -44,6 +44,7 @@ type SocketVFS2 struct {
 	vfs.FileDescriptionDefaultImpl
 	vfs.DentryMetadataFileDescriptionImpl
 	vfs.LockFD
+	vfs.SpliceInFD
 
 	socketVFS2Refs
 	socketOpsCommon
diff --git a/pkg/sentry/syscalls/linux/vfs2/splice.go b/pkg/sentry/syscalls/linux/vfs2/splice.go
index d8580b44a..aee74c0e1 100644
--- a/pkg/sentry/syscalls/linux/vfs2/splice.go
+++ b/pkg/sentry/syscalls/linux/vfs2/splice.go
@@ -70,6 +70,9 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
 	if !inFile.IsReadable() || !outFile.IsWritable() {
 		return 0, nil, linuxerr.EBADF
 	}
+	if !outFile.Impl().SpliceInSupported() {
+		return 0, nil, linuxerr.EINVAL
+	}
 
 	// The operation is non-blocking if anything is non-blocking.
 	//
@@ -213,6 +216,9 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo
 	if !inFile.IsReadable() || !outFile.IsWritable() {
 		return 0, nil, linuxerr.EBADF
 	}
+	if !outFile.Impl().SpliceInSupported() {
+		return 0, nil, linuxerr.EINVAL
+	}
 
 	// The operation is non-blocking if anything is non-blocking.
 	//
@@ -285,6 +291,9 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
 	if !outFile.IsWritable() {
 		return 0, nil, linuxerr.EBADF
 	}
+	if !outFile.Impl().SpliceInSupported() {
+		return 0, nil, linuxerr.EINVAL
+	}
 
 	// Verify that the outFile Append flag is not set.
 	if outFile.StatusFlags()&linux.O_APPEND != 0 {
diff --git a/pkg/sentry/vfs/epoll.go b/pkg/sentry/vfs/epoll.go
index 128e743f3..e27872671 100644
--- a/pkg/sentry/vfs/epoll.go
+++ b/pkg/sentry/vfs/epoll.go
@@ -34,6 +34,7 @@ type EpollInstance struct {
 	FileDescriptionDefaultImpl
 	DentryMetadataFileDescriptionImpl
 	NoLockFD
+	NoSpliceInFD
 
 	// q holds waiters on this EpollInstance.
 	q waiter.Queue
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index 76188b68b..d979d819e 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -473,6 +473,9 @@ type FileDescriptionImpl interface {
 
 	// TestPOSIX returns information about whether the specified lock can be held, in the style of the F_GETLK fcntl.
 	TestPOSIX(ctx context.Context, uid lock.UniqueID, t lock.LockType, r lock.LockRange) (linux.Flock, error)
+
+	// SpliceInSupported returns true if splice into this descriptor is allowed.
+	SpliceInSupported() bool
 }
 
 // Dirent holds the information contained in struct linux_dirent64.
diff --git a/pkg/sentry/vfs/file_description_impl_util.go b/pkg/sentry/vfs/file_description_impl_util.go
index f8b35f248..6628ffaba 100644
--- a/pkg/sentry/vfs/file_description_impl_util.go
+++ b/pkg/sentry/vfs/file_description_impl_util.go
@@ -199,6 +199,11 @@ func (DirectoryFileDescriptionDefaultImpl) Write(ctx context.Context, src userme
 	return 0, linuxerr.EISDIR
 }
 
+// SpliceInSupported implements FileDescriptionImpl.SpliceInSupported.
+func (DirectoryFileDescriptionDefaultImpl) SpliceInSupported() bool {
+	return false
+}
+
 // DentryMetadataFileDescriptionImpl may be embedded by implementations of
 // FileDescriptionImpl for which FileDescriptionOptions.UseDentryMetadata is
 // true to obtain implementations of Stat and SetStat that panic.
@@ -530,3 +535,25 @@ func (BadLockFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, r fslock.
 func (BadLockFD) TestPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, r fslock.LockRange) (linux.Flock, error) {
 	return linux.Flock{}, linuxerr.EBADF
 }
+
+// SpliceInFD implements SpliceInSupported of FileDescriptionImpl interface
+// returning true.
+//
+// +stateify savable
+type SpliceInFD struct{}
+
+// SpliceInSupported implements FileDescriptionImpl.SpliceInSupported.
+func (SpliceInFD) SpliceInSupported() bool {
+	return true
+}
+
+// NoSpliceInFD implements SpliceInSupported of FileDescriptionImpl interface
+// returning false.
+//
+// +stateify savable
+type NoSpliceInFD struct{}
+
+// SpliceInSupported implements FileDescriptionImpl.SpliceInSupported.
+func (NoSpliceInFD) SpliceInSupported() bool {
+	return false
+}
diff --git a/pkg/sentry/vfs/file_description_impl_util_test.go b/pkg/sentry/vfs/file_description_impl_util_test.go
index e34a8c11b..533925060 100644
--- a/pkg/sentry/vfs/file_description_impl_util_test.go
+++ b/pkg/sentry/vfs/file_description_impl_util_test.go
@@ -34,6 +34,7 @@ type fileDescription struct {
 	vfsfd FileDescription
 	FileDescriptionDefaultImpl
 	NoLockFD
+	NoSpliceInFD
 }
 
 // genCount contains the number of times its DynamicBytesSource.Generate()
diff --git a/pkg/sentry/vfs/inotify.go b/pkg/sentry/vfs/inotify.go
index 9b5e63317..0165b5963 100644
--- a/pkg/sentry/vfs/inotify.go
+++ b/pkg/sentry/vfs/inotify.go
@@ -58,6 +58,7 @@ type Inotify struct {
 	FileDescriptionDefaultImpl
 	DentryMetadataFileDescriptionImpl
 	NoLockFD
+	NoSpliceInFD
 
 	// Unique identifier for this inotify instance. We don't just reuse the
 	// inotify fd because fds can be duped. These should not be exposed to the
diff --git a/pkg/sentry/vfs/opath.go b/pkg/sentry/vfs/opath.go
index da0b33b79..461681fae 100644
--- a/pkg/sentry/vfs/opath.go
+++ b/pkg/sentry/vfs/opath.go
@@ -31,6 +31,7 @@ type opathFD struct {
 	vfsfd FileDescription
 	FileDescriptionDefaultImpl
 	BadLockFD
+	NoSpliceInFD
 }
 
 // Release implements FileDescriptionImpl.Release.