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Combine file mode and isDir arguments

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Updates #1035

PiperOrigin-RevId: 303021328
This commit is contained in:
Fabricio Voznika
2020-03-26 08:48:04 -07:00
committed by gVisor bot
parent ce0a69ea97
commit de694e5484
12 changed files with 56 additions and 61 deletions
Download Patch File Download Diff File Expand all files Collapse all files
pkg/abi/linux/file.go
+5
View File
@@ -287,6 +287,11 @@ func (m FileMode) ExtraBits() FileMode {
return m &^ (PermissionsMask | FileTypeMask)
}
// IsDir returns true if file type represents a directory.
func (m FileMode) IsDir() bool {
return m.FileType() == S_IFDIR
}
// String returns a string representation of m.
func (m FileMode) String() string {
var s []string
pkg/sentry/fsimpl/ext/inode.go
+1 -1
View File
@@ -186,7 +186,7 @@ func (in *inode) open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts *vfs.OpenOpt
}
func (in *inode) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) error {
return vfs.GenericCheckPermissions(creds, ats, in.isDir(), uint16(in.diskInode.Mode()), in.diskInode.UID(), in.diskInode.GID())
return vfs.GenericCheckPermissions(creds, ats, in.diskInode.Mode(), in.diskInode.UID(), in.diskInode.GID())
}
// statTo writes the statx fields to the output parameter.
pkg/sentry/fsimpl/gofer/filesystem.go
+11 -11
View File
@@ -119,7 +119,7 @@ func (fs *filesystem) stepLocked(ctx context.Context, rp *vfs.ResolvingPath, d *
if !d.isDir() {
return nil, syserror.ENOTDIR
}
if err := d.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
if err := d.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
afterSymlink:
@@ -314,7 +314,7 @@ func (fs *filesystem) doCreateAt(ctx context.Context, rp *vfs.ResolvingPath, dir
if err != nil {
return err
}
if err := parent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true); err != nil {
if err := parent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
if parent.isDeleted() {
@@ -378,7 +378,7 @@ func (fs *filesystem) unlinkAt(ctx context.Context, rp *vfs.ResolvingPath, dir b
if err != nil {
return err
}
if err := parent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true); err != nil {
if err := parent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
if err := rp.Mount().CheckBeginWrite(); err != nil {
@@ -512,7 +512,7 @@ func (fs *filesystem) AccessAt(ctx context.Context, rp *vfs.ResolvingPath, creds
if err != nil {
return err
}
return d.checkPermissions(creds, ats, d.isDir())
return d.checkPermissions(creds, ats)
}
// GetDentryAt implements vfs.FilesystemImpl.GetDentryAt.
@@ -528,7 +528,7 @@ func (fs *filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, op
if !d.isDir() {
return nil, syserror.ENOTDIR
}
if err := d.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
if err := d.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
}
@@ -624,7 +624,7 @@ afterTrailingSymlink:
return nil, err
}
// Check for search permission in the parent directory.
if err := parent.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
if err := parent.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
// Determine whether or not we need to create a file.
@@ -661,7 +661,7 @@ afterTrailingSymlink:
// Preconditions: fs.renameMu must be locked.
func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.OpenOptions) (*vfs.FileDescription, error) {
ats := vfs.AccessTypesForOpenFlags(opts)
if err := d.checkPermissions(rp.Credentials(), ats, d.isDir()); err != nil {
if err := d.checkPermissions(rp.Credentials(), ats); err != nil {
return nil, err
}
mnt := rp.Mount()
@@ -722,7 +722,7 @@ func (d *dentry) openLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vf
// Preconditions: d.fs.renameMu must be locked. d.dirMu must be locked.
func (d *dentry) createAndOpenChildLocked(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.OpenOptions) (*vfs.FileDescription, error) {
if err := d.checkPermissions(rp.Credentials(), vfs.MayWrite, true); err != nil {
if err := d.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
return nil, err
}
if d.isDeleted() {
@@ -884,7 +884,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
return err
}
}
if err := oldParent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true); err != nil {
if err := oldParent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
vfsObj := rp.VirtualFilesystem()
@@ -904,7 +904,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
return syserror.EINVAL
}
if oldParent != newParent {
if err := renamed.checkPermissions(rp.Credentials(), vfs.MayWrite, true); err != nil {
if err := renamed.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
return err
}
}
@@ -915,7 +915,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
}
if oldParent != newParent {
if err := newParent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true); err != nil {
if err := newParent.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
newParent.dirMu.Lock()
pkg/sentry/fsimpl/gofer/gofer.go
+4 -3
View File
@@ -721,7 +721,8 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
if stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID|linux.STATX_ATIME|linux.STATX_MTIME|linux.STATX_SIZE) != 0 {
return syserror.EPERM
}
if err := vfs.CheckSetStat(ctx, creds, stat, uint16(atomic.LoadUint32(&d.mode))&^linux.S_IFMT, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
mode := linux.FileMode(atomic.LoadUint32(&d.mode))
if err := vfs.CheckSetStat(ctx, creds, stat, mode, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid))); err != nil {
return err
}
if err := mnt.CheckBeginWrite(); err != nil {
@@ -843,8 +844,8 @@ func (d *dentry) setStat(ctx context.Context, creds *auth.Credentials, stat *lin
return nil
}
func (d *dentry) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes, isDir bool) error {
return vfs.GenericCheckPermissions(creds, ats, isDir, uint16(atomic.LoadUint32(&d.mode))&0777, auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid)))
func (d *dentry) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) error {
return vfs.GenericCheckPermissions(creds, ats, linux.FileMode(atomic.LoadUint32(&d.mode)), auth.KUID(atomic.LoadUint32(&d.uid)), auth.KGID(atomic.LoadUint32(&d.gid)))
}
// IncRef implements vfs.DentryImpl.IncRef.
pkg/sentry/fsimpl/host/host.go
+3 -3
View File
@@ -167,8 +167,8 @@ func fileFlagsFromHostFD(fd int) (int, error) {
}
// CheckPermissions implements kernfs.Inode.
func (i *inode) CheckPermissions(ctx context.Context, creds *auth.Credentials, atx vfs.AccessTypes) error {
return vfs.GenericCheckPermissions(creds, atx, false /* isDir */, uint16(i.mode), i.uid, i.gid)
func (i *inode) CheckPermissions(ctx context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error {
return vfs.GenericCheckPermissions(creds, ats, i.mode, i.uid, i.gid)
}
// Mode implements kernfs.Inode.
@@ -306,7 +306,7 @@ func (i *inode) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *auth.Cre
if m&^(linux.STATX_MODE|linux.STATX_SIZE|linux.STATX_ATIME|linux.STATX_MTIME) != 0 {
return syserror.EPERM
}
if err := vfs.CheckSetStat(ctx, creds, &s, uint16(i.Mode().Permissions()), i.uid, i.gid); err != nil {
if err := vfs.CheckSetStat(ctx, creds, &s, i.Mode(), i.uid, i.gid); err != nil {
return err
}
pkg/sentry/fsimpl/kernfs/fd_impl_util.go
+1 -2
View File
@@ -206,8 +206,7 @@ func (fd *GenericDirectoryFD) Stat(ctx context.Context, opts vfs.StatOptions) (l
// SetStat implements vfs.FileDescriptionImpl.SetStat.
func (fd *GenericDirectoryFD) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
fs := fd.filesystem()
creds := auth.CredentialsFromContext(ctx)
inode := fd.vfsfd.VirtualDentry().Dentry().Impl().(*Dentry).inode
return inode.SetStat(ctx, fs, creds, opts)
return inode.SetStat(ctx, fd.filesystem(), creds, opts)
}
pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+2 -4
View File
@@ -241,7 +241,7 @@ func (a *InodeAttrs) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *aut
if opts.Stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID) != 0 {
return syserror.EPERM
}
if err := vfs.CheckSetStat(ctx, creds, &opts.Stat, uint16(a.Mode().Permissions()), auth.KUID(atomic.LoadUint32(&a.uid)), auth.KGID(atomic.LoadUint32(&a.gid))); err != nil {
if err := vfs.CheckSetStat(ctx, creds, &opts.Stat, a.Mode(), auth.KUID(atomic.LoadUint32(&a.uid)), auth.KGID(atomic.LoadUint32(&a.gid))); err != nil {
return err
}
@@ -273,12 +273,10 @@ func (a *InodeAttrs) SetStat(ctx context.Context, fs *vfs.Filesystem, creds *aut
// CheckPermissions implements Inode.CheckPermissions.
func (a *InodeAttrs) CheckPermissions(_ context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error {
mode := a.Mode()
return vfs.GenericCheckPermissions(
creds,
ats,
mode.FileType() == linux.ModeDirectory,
uint16(mode),
a.Mode(),
auth.KUID(atomic.LoadUint32(&a.uid)),
auth.KGID(atomic.LoadUint32(&a.gid)),
)
pkg/sentry/fsimpl/proc/task.go
+1 -8
View File
@@ -172,14 +172,7 @@ func (i *taskOwnedInode) Stat(fs *vfs.Filesystem, opts vfs.StatOptions) (linux.S
func (i *taskOwnedInode) CheckPermissions(_ context.Context, creds *auth.Credentials, ats vfs.AccessTypes) error {
mode := i.Mode()
uid, gid := i.getOwner(mode)
return vfs.GenericCheckPermissions(
creds,
ats,
mode.FileType() == linux.ModeDirectory,
uint16(mode),
uid,
gid,
)
return vfs.GenericCheckPermissions(creds, ats, mode, uid, gid)
}
func (i *taskOwnedInode) getOwner(mode linux.FileMode) (auth.KUID, auth.KGID) {
pkg/sentry/fsimpl/tmpfs/filesystem.go
+12 -12
View File
@@ -41,7 +41,7 @@ func stepLocked(rp *vfs.ResolvingPath, d *dentry) (*dentry, error) {
if !d.inode.isDir() {
return nil, syserror.ENOTDIR
}
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
afterSymlink:
@@ -125,7 +125,7 @@ func (fs *filesystem) doCreateAt(rp *vfs.ResolvingPath, dir bool, create func(pa
if err != nil {
return err
}
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
name := rp.Component()
@@ -163,7 +163,7 @@ func (fs *filesystem) AccessAt(ctx context.Context, rp *vfs.ResolvingPath, creds
if err != nil {
return err
}
return d.inode.checkPermissions(creds, ats, d.inode.isDir())
return d.inode.checkPermissions(creds, ats)
}
// GetDentryAt implements vfs.FilesystemImpl.GetDentryAt.
@@ -178,7 +178,7 @@ func (fs *filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, op
if !d.inode.isDir() {
return nil, syserror.ENOTDIR
}
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec, true /* isDir */); err != nil {
if err := d.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
}
@@ -301,7 +301,7 @@ afterTrailingSymlink:
return nil, err
}
// Check for search permission in the parent directory.
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayExec, true); err != nil {
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayExec); err != nil {
return nil, err
}
// Reject attempts to open directories with O_CREAT.
@@ -316,7 +316,7 @@ afterTrailingSymlink:
child, err := stepLocked(rp, parent)
if err == syserror.ENOENT {
// Already checked for searchability above; now check for writability.
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite, true); err != nil {
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
return nil, err
}
if err := rp.Mount().CheckBeginWrite(); err != nil {
@@ -347,7 +347,7 @@ afterTrailingSymlink:
func (d *dentry) open(ctx context.Context, rp *vfs.ResolvingPath, opts *vfs.OpenOptions, afterCreate bool) (*vfs.FileDescription, error) {
ats := vfs.AccessTypesForOpenFlags(opts)
if !afterCreate {
if err := d.inode.checkPermissions(rp.Credentials(), ats, d.inode.isDir()); err != nil {
if err := d.inode.checkPermissions(rp.Credentials(), ats); err != nil {
return nil, err
}
}
@@ -428,7 +428,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
defer mnt.EndWrite()
oldParent := oldParentVD.Dentry().Impl().(*dentry)
if err := oldParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
if err := oldParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
// Call vfs.Dentry.Child() instead of stepLocked() or rp.ResolveChild(),
@@ -445,7 +445,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
}
if oldParent != newParent {
// Writability is needed to change renamed's "..".
if err := renamed.inode.checkPermissions(rp.Credentials(), vfs.MayWrite, true /* isDir */); err != nil {
if err := renamed.inode.checkPermissions(rp.Credentials(), vfs.MayWrite); err != nil {
return err
}
}
@@ -455,7 +455,7 @@ func (fs *filesystem) RenameAt(ctx context.Context, rp *vfs.ResolvingPath, oldPa
}
}
if err := newParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
if err := newParent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
replacedVFSD := newParent.vfsd.Child(newName)
@@ -528,7 +528,7 @@ func (fs *filesystem) RmdirAt(ctx context.Context, rp *vfs.ResolvingPath) error
if err != nil {
return err
}
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
name := rp.Component()
@@ -621,7 +621,7 @@ func (fs *filesystem) UnlinkAt(ctx context.Context, rp *vfs.ResolvingPath) error
if err != nil {
return err
}
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec, true /* isDir */); err != nil {
if err := parent.inode.checkPermissions(rp.Credentials(), vfs.MayWrite|vfs.MayExec); err != nil {
return err
}
name := rp.Component()
pkg/sentry/fsimpl/tmpfs/tmpfs.go
+5 -3
View File
@@ -245,8 +245,9 @@ func (i *inode) decRef() {
}
}
func (i *inode) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes, isDir bool) error {
return vfs.GenericCheckPermissions(creds, ats, isDir, uint16(atomic.LoadUint32(&i.mode)), auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid)))
func (i *inode) checkPermissions(creds *auth.Credentials, ats vfs.AccessTypes) error {
mode := linux.FileMode(atomic.LoadUint32(&i.mode))
return vfs.GenericCheckPermissions(creds, ats, mode, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid)))
}
// Go won't inline this function, and returning linux.Statx (which is quite
@@ -299,7 +300,8 @@ func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linu
if stat.Mask&^(linux.STATX_MODE|linux.STATX_UID|linux.STATX_GID|linux.STATX_ATIME|linux.STATX_MTIME|linux.STATX_CTIME|linux.STATX_SIZE) != 0 {
return syserror.EPERM
}
if err := vfs.CheckSetStat(ctx, creds, stat, uint16(atomic.LoadUint32(&i.mode))&^linux.S_IFMT, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid))); err != nil {
mode := linux.FileMode(atomic.LoadUint32(&i.mode))
if err := vfs.CheckSetStat(ctx, creds, stat, mode, auth.KUID(atomic.LoadUint32(&i.uid)), auth.KGID(atomic.LoadUint32(&i.gid))); err != nil {
return err
}
i.mu.Lock()
pkg/sentry/vfs/anonfs.go
+1 -1
View File
@@ -83,7 +83,7 @@ func (fs *anonFilesystem) AccessAt(ctx context.Context, rp *ResolvingPath, creds
if !rp.Done() {
return syserror.ENOTDIR
}
return GenericCheckPermissions(creds, ats, false /* isDir */, anonFileMode, anonFileUID, anonFileGID)
return GenericCheckPermissions(creds, ats, anonFileMode, anonFileUID, anonFileGID)
}
// GetDentryAt implements FilesystemImpl.GetDentryAt.
pkg/sentry/vfs/permissions.go
+10 -13
View File
@@ -29,9 +29,9 @@ type AccessTypes uint16
// Bits in AccessTypes.
const (
MayExec AccessTypes = 1
MayWrite AccessTypes = 2
MayRead AccessTypes = 4
MayWrite = 2
MayExec = 1
)
// OnlyRead returns true if access _only_ allows read.
@@ -56,16 +56,17 @@ func (a AccessTypes) MayExec() bool {
// GenericCheckPermissions checks that creds has the given access rights on a
// file with the given permissions, UID, and GID, subject to the rules of
// fs/namei.c:generic_permission(). isDir is true if the file is a directory.
func GenericCheckPermissions(creds *auth.Credentials, ats AccessTypes, isDir bool, mode uint16, kuid auth.KUID, kgid auth.KGID) error {
// fs/namei.c:generic_permission().
func GenericCheckPermissions(creds *auth.Credentials, ats AccessTypes, mode linux.FileMode, kuid auth.KUID, kgid auth.KGID) error {
// Check permission bits.
perms := mode
perms := uint16(mode.Permissions())
if creds.EffectiveKUID == kuid {
perms >>= 6
} else if creds.InGroup(kgid) {
perms >>= 3
}
if uint16(ats)&perms == uint16(ats) {
// All permission bits match, access granted.
return nil
}
@@ -77,7 +78,7 @@ func GenericCheckPermissions(creds *auth.Credentials, ats AccessTypes, isDir boo
}
// CAP_DAC_READ_SEARCH allows the caller to read and search arbitrary
// directories, and read arbitrary non-directory files.
if (isDir && !ats.MayWrite()) || ats.OnlyRead() {
if (mode.IsDir() && !ats.MayWrite()) || ats.OnlyRead() {
if creds.HasCapability(linux.CAP_DAC_READ_SEARCH) {
return nil
}
@@ -85,7 +86,7 @@ func GenericCheckPermissions(creds *auth.Credentials, ats AccessTypes, isDir boo
// CAP_DAC_OVERRIDE allows arbitrary access to directories, read/write
// access to non-directory files, and execute access to non-directory files
// for which at least one execute bit is set.
if isDir || !ats.MayExec() || (mode&0111 != 0) {
if mode.IsDir() || !ats.MayExec() || (mode.Permissions()&0111 != 0) {
if creds.HasCapability(linux.CAP_DAC_OVERRIDE) {
return nil
}
@@ -151,7 +152,7 @@ func MayWriteFileWithOpenFlags(flags uint32) bool {
// CheckSetStat checks that creds has permission to change the metadata of a
// file with the given permissions, UID, and GID as specified by stat, subject
// to the rules of Linux's fs/attr.c:setattr_prepare().
func CheckSetStat(ctx context.Context, creds *auth.Credentials, stat *linux.Statx, mode uint16, kuid auth.KUID, kgid auth.KGID) error {
func CheckSetStat(ctx context.Context, creds *auth.Credentials, stat *linux.Statx, mode linux.FileMode, kuid auth.KUID, kgid auth.KGID) error {
if stat.Mask&linux.STATX_SIZE != 0 {
limit, err := CheckLimit(ctx, 0, int64(stat.Size))
if err != nil {
@@ -190,11 +191,7 @@ func CheckSetStat(ctx context.Context, creds *auth.Credentials, stat *linux.Stat
(stat.Mask&linux.STATX_CTIME != 0 && stat.Ctime.Nsec != linux.UTIME_NOW) {
return syserror.EPERM
}
// isDir is irrelevant in the following call to
// GenericCheckPermissions since ats == MayWrite means that
// CAP_DAC_READ_SEARCH does not apply, and CAP_DAC_OVERRIDE
// applies, regardless of isDir.
if err := GenericCheckPermissions(creds, MayWrite, false /* isDir */, mode, kuid, kgid); err != nil {
if err := GenericCheckPermissions(creds, MayWrite, mode, kuid, kgid); err != nil {
return err
}
}