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-rw-r--r--pkg/sentry/fsimpl/tmpfs/device_file.go10
-rw-r--r--pkg/sentry/fsimpl/tmpfs/directory.go7
-rw-r--r--pkg/sentry/fsimpl/tmpfs/filesystem.go36
-rw-r--r--pkg/sentry/fsimpl/tmpfs/named_pipe.go2
-rw-r--r--pkg/sentry/fsimpl/tmpfs/regular_file.go13
-rw-r--r--pkg/sentry/fsimpl/tmpfs/symlink.go3
-rw-r--r--pkg/sentry/fsimpl/tmpfs/tmpfs.go43
7 files changed, 73 insertions, 41 deletions
diff --git a/pkg/sentry/fsimpl/tmpfs/device_file.go b/pkg/sentry/fsimpl/tmpfs/device_file.go
index 84b181b90..83bf885ee 100644
--- a/pkg/sentry/fsimpl/tmpfs/device_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/device_file.go
@@ -15,6 +15,8 @@
package tmpfs
import (
+ "fmt"
+
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/vfs"
@@ -33,6 +35,14 @@ func (fs *filesystem) newDeviceFile(creds *auth.Credentials, mode linux.FileMode
major: major,
minor: minor,
}
+ switch kind {
+ case vfs.BlockDevice:
+ mode |= linux.S_IFBLK
+ case vfs.CharDevice:
+ mode |= linux.S_IFCHR
+ default:
+ panic(fmt.Sprintf("invalid DeviceKind: %v", kind))
+ }
file.inode.init(file, fs, creds, mode)
file.inode.nlink = 1 // from parent directory
return &file.inode
diff --git a/pkg/sentry/fsimpl/tmpfs/directory.go b/pkg/sentry/fsimpl/tmpfs/directory.go
index b4380af38..37c75ab64 100644
--- a/pkg/sentry/fsimpl/tmpfs/directory.go
+++ b/pkg/sentry/fsimpl/tmpfs/directory.go
@@ -34,16 +34,11 @@ type directory struct {
func (fs *filesystem) newDirectory(creds *auth.Credentials, mode linux.FileMode) *inode {
dir := &directory{}
- dir.inode.init(dir, fs, creds, mode)
+ dir.inode.init(dir, fs, creds, linux.S_IFDIR|mode)
dir.inode.nlink = 2 // from "." and parent directory or ".." for root
return &dir.inode
}
-func (i *inode) isDir() bool {
- _, ok := i.impl.(*directory)
- return ok
-}
-
type directoryFD struct {
fileDescription
vfs.DirectoryFileDescriptionDefaultImpl
diff --git a/pkg/sentry/fsimpl/tmpfs/filesystem.go b/pkg/sentry/fsimpl/tmpfs/filesystem.go
index e1b551422..12cc64385 100644
--- a/pkg/sentry/fsimpl/tmpfs/filesystem.go
+++ b/pkg/sentry/fsimpl/tmpfs/filesystem.go
@@ -20,6 +20,7 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
)
@@ -40,7 +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:
@@ -124,7 +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()
@@ -154,6 +155,17 @@ func (fs *filesystem) doCreateAt(rp *vfs.ResolvingPath, dir bool, create func(pa
return create(parent, name)
}
+// AccessAt implements vfs.Filesystem.Impl.AccessAt.
+func (fs *filesystem) AccessAt(ctx context.Context, rp *vfs.ResolvingPath, creds *auth.Credentials, ats vfs.AccessTypes) error {
+ fs.mu.RLock()
+ defer fs.mu.RUnlock()
+ d, err := resolveLocked(rp)
+ if err != nil {
+ return err
+ }
+ return d.inode.checkPermissions(creds, ats)
+}
+
// GetDentryAt implements vfs.FilesystemImpl.GetDentryAt.
func (fs *filesystem) GetDentryAt(ctx context.Context, rp *vfs.ResolvingPath, opts vfs.GetDentryOptions) (*vfs.Dentry, error) {
fs.mu.RLock()
@@ -166,7 +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
}
}
@@ -289,7 +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.
@@ -304,7 +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 {
@@ -335,7 +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
}
}
@@ -416,7 +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(),
@@ -433,7 +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
}
}
@@ -443,7 +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)
@@ -516,7 +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()
@@ -563,7 +575,7 @@ func (fs *filesystem) SetStatAt(ctx context.Context, rp *vfs.ResolvingPath, opts
if err != nil {
return err
}
- return d.inode.setStat(opts.Stat)
+ return d.inode.setStat(ctx, rp.Credentials(), &opts.Stat)
}
// StatAt implements vfs.FilesystemImpl.StatAt.
@@ -609,7 +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()
diff --git a/pkg/sentry/fsimpl/tmpfs/named_pipe.go b/pkg/sentry/fsimpl/tmpfs/named_pipe.go
index 0c57fdca3..2c5c739df 100644
--- a/pkg/sentry/fsimpl/tmpfs/named_pipe.go
+++ b/pkg/sentry/fsimpl/tmpfs/named_pipe.go
@@ -34,7 +34,7 @@ type namedPipe struct {
// * rp.Mount().CheckBeginWrite() has been called successfully.
func (fs *filesystem) newNamedPipe(creds *auth.Credentials, mode linux.FileMode) *inode {
file := &namedPipe{pipe: pipe.NewVFSPipe(pipe.DefaultPipeSize, usermem.PageSize)}
- file.inode.init(file, fs, creds, mode)
+ file.inode.init(file, fs, creds, linux.S_IFIFO|mode)
file.inode.nlink = 1 // Only the parent has a link.
return &file.inode
}
diff --git a/pkg/sentry/fsimpl/tmpfs/regular_file.go b/pkg/sentry/fsimpl/tmpfs/regular_file.go
index 711442424..26cd65605 100644
--- a/pkg/sentry/fsimpl/tmpfs/regular_file.go
+++ b/pkg/sentry/fsimpl/tmpfs/regular_file.go
@@ -89,7 +89,7 @@ func (fs *filesystem) newRegularFile(creds *auth.Credentials, mode linux.FileMod
file := &regularFile{
memFile: fs.memFile,
}
- file.inode.init(file, fs, creds, mode)
+ file.inode.init(file, fs, creds, linux.S_IFREG|mode)
file.inode.nlink = 1 // from parent directory
return &file.inode
}
@@ -308,11 +308,18 @@ func (fd *regularFileFD) PWrite(ctx context.Context, src usermem.IOSequence, off
return 0, nil
}
f := fd.inode().impl.(*regularFile)
- end := offset + srclen
- if end < offset {
+ if end := offset + srclen; end < offset {
// Overflow.
return 0, syserror.EFBIG
}
+
+ var err error
+ srclen, err = vfs.CheckLimit(ctx, offset, srclen)
+ if err != nil {
+ return 0, err
+ }
+ src = src.TakeFirst64(srclen)
+
f.inode.mu.Lock()
rw := getRegularFileReadWriter(f, offset)
n, err := src.CopyInTo(ctx, rw)
diff --git a/pkg/sentry/fsimpl/tmpfs/symlink.go b/pkg/sentry/fsimpl/tmpfs/symlink.go
index 5246aca84..47e075ed4 100644
--- a/pkg/sentry/fsimpl/tmpfs/symlink.go
+++ b/pkg/sentry/fsimpl/tmpfs/symlink.go
@@ -15,6 +15,7 @@
package tmpfs
import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
)
@@ -27,7 +28,7 @@ func (fs *filesystem) newSymlink(creds *auth.Credentials, target string) *inode
link := &symlink{
target: target,
}
- link.inode.init(link, fs, creds, 0777)
+ link.inode.init(link, fs, creds, linux.S_IFLNK|0777)
link.inode.nlink = 1 // from parent directory
return &link.inode
}
diff --git a/pkg/sentry/fsimpl/tmpfs/tmpfs.go b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
index 521206305..2f9e6c876 100644
--- a/pkg/sentry/fsimpl/tmpfs/tmpfs.go
+++ b/pkg/sentry/fsimpl/tmpfs/tmpfs.go
@@ -144,7 +144,7 @@ type inode struct {
// Inode metadata. Writing multiple fields atomically requires holding
// mu, othewise atomic operations can be used.
mu sync.Mutex
- mode uint32 // excluding file type bits, which are based on impl
+ mode uint32 // file type and mode
nlink uint32 // protected by filesystem.mu instead of inode.mu
uid uint32 // auth.KUID, but stored as raw uint32 for sync/atomic
gid uint32 // auth.KGID, but ...
@@ -168,6 +168,9 @@ type inode struct {
const maxLinks = math.MaxUint32
func (i *inode) init(impl interface{}, fs *filesystem, creds *auth.Credentials, mode linux.FileMode) {
+ if mode.FileType() == 0 {
+ panic("file type is required in FileMode")
+ }
i.clock = fs.clock
i.refs = 1
i.mode = uint32(mode)
@@ -242,8 +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
@@ -269,40 +273,37 @@ func (i *inode) statTo(stat *linux.Statx) {
// TODO(gvisor.dev/issues/1197): Device number.
switch impl := i.impl.(type) {
case *regularFile:
- stat.Mode |= linux.S_IFREG
stat.Mask |= linux.STATX_SIZE | linux.STATX_BLOCKS
stat.Size = uint64(atomic.LoadUint64(&impl.size))
// In tmpfs, this will be FileRangeSet.Span() / 512 (but also cached in
// a uint64 accessed using atomic memory operations to avoid taking
// locks).
stat.Blocks = allocatedBlocksForSize(stat.Size)
- case *directory:
- stat.Mode |= linux.S_IFDIR
case *symlink:
- stat.Mode |= linux.S_IFLNK
stat.Mask |= linux.STATX_SIZE | linux.STATX_BLOCKS
stat.Size = uint64(len(impl.target))
stat.Blocks = allocatedBlocksForSize(stat.Size)
- case *namedPipe:
- stat.Mode |= linux.S_IFIFO
case *deviceFile:
- switch impl.kind {
- case vfs.BlockDevice:
- stat.Mode |= linux.S_IFBLK
- case vfs.CharDevice:
- stat.Mode |= linux.S_IFCHR
- }
stat.RdevMajor = impl.major
stat.RdevMinor = impl.minor
+ case *directory, *namedPipe:
+ // Nothing to do.
default:
panic(fmt.Sprintf("unknown inode type: %T", i.impl))
}
}
-func (i *inode) setStat(stat linux.Statx) error {
+func (i *inode) setStat(ctx context.Context, creds *auth.Credentials, stat *linux.Statx) error {
if stat.Mask == 0 {
return nil
}
+ 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
+ }
+ 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()
var (
needsMtimeBump bool
@@ -310,7 +311,8 @@ func (i *inode) setStat(stat linux.Statx) error {
)
mask := stat.Mask
if mask&linux.STATX_MODE != 0 {
- atomic.StoreUint32(&i.mode, uint32(stat.Mode))
+ ft := atomic.LoadUint32(&i.mode) & linux.S_IFMT
+ atomic.StoreUint32(&i.mode, ft|uint32(stat.Mode&^linux.S_IFMT))
needsCtimeBump = true
}
if mask&linux.STATX_UID != 0 {
@@ -433,6 +435,10 @@ func (i *inode) direntType() uint8 {
}
}
+func (i *inode) isDir() bool {
+ return linux.FileMode(i.mode).FileType() == linux.S_IFDIR
+}
+
// fileDescription is embedded by tmpfs implementations of
// vfs.FileDescriptionImpl.
type fileDescription struct {
@@ -457,5 +463,6 @@ func (fd *fileDescription) Stat(ctx context.Context, opts vfs.StatOptions) (linu
// SetStat implements vfs.FileDescriptionImpl.SetStat.
func (fd *fileDescription) SetStat(ctx context.Context, opts vfs.SetStatOptions) error {
- return fd.inode().setStat(opts.Stat)
+ creds := auth.CredentialsFromContext(ctx)
+ return fd.inode().setStat(ctx, creds, &opts.Stat)
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-08 05:54:31 +0000