diff options
-rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/fd.go | 13 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/ioctl.go | 4 | ||||
-rw-r--r-- | pkg/sentry/syscalls/linux/vfs2/sync.go | 4 | ||||
-rw-r--r-- | pkg/sentry/vfs/opath.go | 139 | ||||
-rw-r--r-- | pkg/sentry/vfs/options.go | 2 | ||||
-rw-r--r-- | pkg/sentry/vfs/vfs.go | 12 | ||||
-rw-r--r-- | pkg/sentry/vfs/vfs_state_autogen.go | 30 |
7 files changed, 203 insertions, 1 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go index e39f074f2..1a31898e8 100644 --- a/pkg/sentry/syscalls/linux/vfs2/fd.go +++ b/pkg/sentry/syscalls/linux/vfs2/fd.go @@ -123,6 +123,15 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall } defer file.DecRef(t) + if file.StatusFlags()&linux.O_PATH != 0 { + switch cmd { + case linux.F_DUPFD, linux.F_DUPFD_CLOEXEC, linux.F_GETFD, linux.F_SETFD, linux.F_GETFL: + // allowed + default: + return 0, nil, syserror.EBADF + } + } + switch cmd { case linux.F_DUPFD, linux.F_DUPFD_CLOEXEC: minfd := args[2].Int() @@ -395,6 +404,10 @@ func Fadvise64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sys } defer file.DecRef(t) + if file.StatusFlags()&linux.O_PATH != 0 { + return 0, nil, syserror.EBADF + } + // If the FD refers to a pipe or FIFO, return error. if _, isPipe := file.Impl().(*pipe.VFSPipeFD); isPipe { return 0, nil, syserror.ESPIPE diff --git a/pkg/sentry/syscalls/linux/vfs2/ioctl.go b/pkg/sentry/syscalls/linux/vfs2/ioctl.go index 20c264fef..c7c3fed57 100644 --- a/pkg/sentry/syscalls/linux/vfs2/ioctl.go +++ b/pkg/sentry/syscalls/linux/vfs2/ioctl.go @@ -32,6 +32,10 @@ func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall } defer file.DecRef(t) + if file.StatusFlags()&linux.O_PATH != 0 { + return 0, nil, syserror.EBADF + } + // Handle ioctls that apply to all FDs. switch args[1].Int() { case linux.FIONCLEX: diff --git a/pkg/sentry/syscalls/linux/vfs2/sync.go b/pkg/sentry/syscalls/linux/vfs2/sync.go index 6e9b599e2..1f8a5878c 100644 --- a/pkg/sentry/syscalls/linux/vfs2/sync.go +++ b/pkg/sentry/syscalls/linux/vfs2/sync.go @@ -36,6 +36,10 @@ func Syncfs(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal } defer file.DecRef(t) + if file.StatusFlags()&linux.O_PATH != 0 { + return 0, nil, syserror.EBADF + } + return 0, nil, file.SyncFS(t) } diff --git a/pkg/sentry/vfs/opath.go b/pkg/sentry/vfs/opath.go new file mode 100644 index 000000000..39fbac987 --- /dev/null +++ b/pkg/sentry/vfs/opath.go @@ -0,0 +1,139 @@ +// Copyright 2019 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package vfs + +import ( + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/context" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/kernel/auth" + "gvisor.dev/gvisor/pkg/sentry/memmap" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/usermem" +) + +// opathFD implements vfs.FileDescriptionImpl for a file description opened with O_PATH. +// +// +stateify savable +type opathFD struct { + vfsfd FileDescription + FileDescriptionDefaultImpl + NoLockFD +} + +// Release implements vfs.FileDescriptionImpl.Release. +func (fd *opathFD) Release(context.Context) { + // noop +} + +// Allocate implements vfs.FileDescriptionImpl.Allocate. +func (fd *opathFD) Allocate(ctx context.Context, mode, offset, length uint64) error { + return syserror.EBADF +} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (fd *opathFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts ReadOptions) (int64, error) { + return 0, syserror.EBADF +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (fd *opathFD) Read(ctx context.Context, dst usermem.IOSequence, opts ReadOptions) (int64, error) { + return 0, syserror.EBADF +} + +// PWrite implements vfs.FileDescriptionImpl.PWrite. +func (fd *opathFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts WriteOptions) (int64, error) { + return 0, syserror.EBADF +} + +// Write implements vfs.FileDescriptionImpl.Write. +func (fd *opathFD) Write(ctx context.Context, src usermem.IOSequence, opts WriteOptions) (int64, error) { + return 0, syserror.EBADF +} + +// Ioctl implements vfs.FileDescriptionImpl.Ioctl. +func (fd *opathFD) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArguments) (uintptr, error) { + return 0, syserror.EBADF +} + +// IterDirents implements vfs.FileDescriptionImpl.IterDirents. +func (fd *opathFD) IterDirents(ctx context.Context, cb IterDirentsCallback) error { + return syserror.EBADF +} + +// Seek implements vfs.FileDescriptionImpl.Seek. +func (fd *opathFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { + return 0, syserror.EBADF +} + +// ConfigureMMap implements vfs.FileDescriptionImpl.ConfigureMMap. +func (fd *opathFD) ConfigureMMap(ctx context.Context, opts *memmap.MMapOpts) error { + return syserror.EBADF +} + +// ListXattr implements vfs.FileDescriptionImpl.ListXattr. +func (fd *opathFD) ListXattr(ctx context.Context, size uint64) ([]string, error) { + return nil, syserror.EBADF +} + +// GetXattr implements vfs.FileDescriptionImpl.GetXattr. +func (fd *opathFD) GetXattr(ctx context.Context, opts GetXattrOptions) (string, error) { + return "", syserror.EBADF +} + +// SetXattr implements vfs.FileDescriptionImpl.SetXattr. +func (fd *opathFD) SetXattr(ctx context.Context, opts SetXattrOptions) error { + return syserror.EBADF +} + +// RemoveXattr implements vfs.FileDescriptionImpl.RemoveXattr. +func (fd *opathFD) RemoveXattr(ctx context.Context, name string) error { + return syserror.EBADF +} + +// Sync implements vfs.FileDescriptionImpl.Sync. +func (fd *opathFD) Sync(ctx context.Context) error { + return syserror.EBADF +} + +// SetStat implements vfs.FileDescriptionImpl.SetStat. +func (fd *opathFD) SetStat(ctx context.Context, opts SetStatOptions) error { + return syserror.EBADF +} + +// Stat implements vfs.FileDescriptionImpl.Stat. +func (fd *opathFD) Stat(ctx context.Context, opts StatOptions) (linux.Statx, error) { + vfsObj := fd.vfsfd.vd.mount.vfs + rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{ + Root: fd.vfsfd.vd, + Start: fd.vfsfd.vd, + }) + stat, err := fd.vfsfd.vd.mount.fs.impl.StatAt(ctx, rp, opts) + vfsObj.putResolvingPath(ctx, rp) + return stat, err +} + +// StatFS returns metadata for the filesystem containing the file represented +// by fd. +func (fd *opathFD) StatFS(ctx context.Context) (linux.Statfs, error) { + vfsObj := fd.vfsfd.vd.mount.vfs + rp := vfsObj.getResolvingPath(auth.CredentialsFromContext(ctx), &PathOperation{ + Root: fd.vfsfd.vd, + Start: fd.vfsfd.vd, + }) + statfs, err := fd.vfsfd.vd.mount.fs.impl.StatFSAt(ctx, rp) + vfsObj.putResolvingPath(ctx, rp) + return statfs, err +} diff --git a/pkg/sentry/vfs/options.go b/pkg/sentry/vfs/options.go index bc79e5ecc..c9907843c 100644 --- a/pkg/sentry/vfs/options.go +++ b/pkg/sentry/vfs/options.go @@ -129,7 +129,7 @@ type OpenOptions struct { // // FilesystemImpls are responsible for implementing the following flags: // O_RDONLY, O_WRONLY, O_RDWR, O_APPEND, O_CREAT, O_DIRECT, O_DSYNC, - // O_EXCL, O_NOATIME, O_NOCTTY, O_NONBLOCK, O_PATH, O_SYNC, O_TMPFILE, and + // O_EXCL, O_NOATIME, O_NOCTTY, O_NONBLOCK, O_SYNC, O_TMPFILE, and // O_TRUNC. VFS is responsible for handling O_DIRECTORY, O_LARGEFILE, and // O_NOFOLLOW. VFS users are responsible for handling O_CLOEXEC, since file // descriptors are mostly outside the scope of VFS. diff --git a/pkg/sentry/vfs/vfs.go b/pkg/sentry/vfs/vfs.go index 6fd1bb0b2..0aff2dd92 100644 --- a/pkg/sentry/vfs/vfs.go +++ b/pkg/sentry/vfs/vfs.go @@ -425,6 +425,18 @@ func (vfs *VirtualFilesystem) OpenAt(ctx context.Context, creds *auth.Credential rp.mustBeDir = true rp.mustBeDirOrig = true } + if opts.Flags&linux.O_PATH != 0 { + vd, err := vfs.GetDentryAt(ctx, creds, pop, &GetDentryOptions{}) + if err != nil { + return nil, err + } + fd := &opathFD{} + if err := fd.vfsfd.Init(fd, opts.Flags, vd.Mount(), vd.Dentry(), &FileDescriptionOptions{}); err != nil { + return nil, err + } + vd.DecRef(ctx) + return &fd.vfsfd, err + } for { fd, err := rp.mount.fs.impl.OpenAt(ctx, rp, *opts) if err == nil { diff --git a/pkg/sentry/vfs/vfs_state_autogen.go b/pkg/sentry/vfs/vfs_state_autogen.go index 006d315be..c048676ea 100644 --- a/pkg/sentry/vfs/vfs_state_autogen.go +++ b/pkg/sentry/vfs/vfs_state_autogen.go @@ -1170,6 +1170,35 @@ func (r *MountNamespaceRefs) StateLoad(stateSourceObject state.Source) { stateSourceObject.AfterLoad(r.afterLoad) } +func (fd *opathFD) StateTypeName() string { + return "pkg/sentry/vfs.opathFD" +} + +func (fd *opathFD) StateFields() []string { + return []string{ + "vfsfd", + "FileDescriptionDefaultImpl", + "NoLockFD", + } +} + +func (fd *opathFD) beforeSave() {} + +func (fd *opathFD) StateSave(stateSinkObject state.Sink) { + fd.beforeSave() + stateSinkObject.Save(0, &fd.vfsfd) + stateSinkObject.Save(1, &fd.FileDescriptionDefaultImpl) + stateSinkObject.Save(2, &fd.NoLockFD) +} + +func (fd *opathFD) afterLoad() {} + +func (fd *opathFD) StateLoad(stateSourceObject state.Source) { + stateSourceObject.Load(0, &fd.vfsfd) + stateSourceObject.Load(1, &fd.FileDescriptionDefaultImpl) + stateSourceObject.Load(2, &fd.NoLockFD) +} + func (g *GetDentryOptions) StateTypeName() string { return "pkg/sentry/vfs.GetDentryOptions" } @@ -1858,6 +1887,7 @@ func init() { state.Register((*MountNamespace)(nil)) state.Register((*umountRecursiveOptions)(nil)) state.Register((*MountNamespaceRefs)(nil)) + state.Register((*opathFD)(nil)) state.Register((*GetDentryOptions)(nil)) state.Register((*MkdirOptions)(nil)) state.Register((*MknodOptions)(nil)) |