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-rw-r--r--pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go7
-rw-r--r--pkg/sentry/fsimpl/kernfs/inode_impl_util.go9
-rw-r--r--pkg/sentry/fsimpl/kernfs/symlink.go7
-rw-r--r--pkg/sentry/fsimpl/proc/subtasks.go5
-rw-r--r--pkg/sentry/fsimpl/proc/task.go10
-rw-r--r--pkg/sentry/fsimpl/proc/tasks.go16
-rw-r--r--pkg/sentry/fsimpl/proc/tasks_files.go33
-rw-r--r--pkg/sentry/fsimpl/sys/sys.go8
8 files changed, 74 insertions, 21 deletions
diff --git a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
index 1c026f4d8..0d27a8867 100644
--- a/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
+++ b/pkg/sentry/fsimpl/kernfs/dynamic_bytes_file.go
@@ -61,9 +61,10 @@ func (f *DynamicBytesFile) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vf
return &fd.vfsfd, nil
}
-// SetStat implements Inode.SetStat.
-func (f *DynamicBytesFile) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
- // DynamicBytesFiles are immutable.
+// SetStat implements Inode.SetStat. By default DynamicBytesFile doesn't allow
+// inode attributes to be changed. Override SetStat() making it call
+// f.InodeAttrs to allow it.
+func (*DynamicBytesFile) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
return syserror.EPERM
}
diff --git a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
index 94ca3dbdd..4ed41326d 100644
--- a/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
+++ b/pkg/sentry/fsimpl/kernfs/inode_impl_util.go
@@ -228,7 +228,7 @@ func (a *InodeAttrs) Stat(*vfs.Filesystem, vfs.StatOptions) (linux.Statx, error)
stat.GID = atomic.LoadUint32(&a.gid)
stat.Nlink = atomic.LoadUint32(&a.nlink)
- // TODO: Implement other stat fields like timestamps.
+ // TODO(gvisor.dev/issue/1193): Implement other stat fields like timestamps.
return stat, nil
}
@@ -256,7 +256,7 @@ func (a *InodeAttrs) SetStat(_ *vfs.Filesystem, opts vfs.SetStatOptions) error {
// Note that not all fields are modifiable. For example, the file type and
// inode numbers are immutable after node creation.
- // TODO: Implement other stat fields like timestamps.
+ // TODO(gvisor.dev/issue/1193): Implement other stat fields like timestamps.
return nil
}
@@ -555,6 +555,11 @@ func (s *StaticDirectory) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs
return fd.VFSFileDescription(), nil
}
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*StaticDirectory) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
+
// AlwaysValid partially implements kernfs.inodeDynamicLookup.
type AlwaysValid struct{}
diff --git a/pkg/sentry/fsimpl/kernfs/symlink.go b/pkg/sentry/fsimpl/kernfs/symlink.go
index 0ee7eb9b7..41c5a3099 100644
--- a/pkg/sentry/fsimpl/kernfs/symlink.go
+++ b/pkg/sentry/fsimpl/kernfs/symlink.go
@@ -18,6 +18,8 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
)
// StaticSymlink provides an Inode implementation for symlinks that point to
@@ -52,3 +54,8 @@ func (s *StaticSymlink) Init(creds *auth.Credentials, ino uint64, target string)
func (s *StaticSymlink) Readlink(_ context.Context) (string, error) {
return s.target, nil
}
+
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*StaticSymlink) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
diff --git a/pkg/sentry/fsimpl/proc/subtasks.go b/pkg/sentry/fsimpl/proc/subtasks.go
index a3a7c16a5..ea6d60f6e 100644
--- a/pkg/sentry/fsimpl/proc/subtasks.go
+++ b/pkg/sentry/fsimpl/proc/subtasks.go
@@ -127,3 +127,8 @@ func (i *subtasksInode) Stat(vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.
}
return stat, nil
}
+
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*subtasksInode) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go
index 4891caab6..fae3fc5aa 100644
--- a/pkg/sentry/fsimpl/proc/task.go
+++ b/pkg/sentry/fsimpl/proc/task.go
@@ -107,13 +107,9 @@ func (i *taskInode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenO
return fd.VFSFileDescription(), nil
}
-// SetStat implements kernfs.Inode.
-func (i *taskInode) SetStat(_ *vfs.Filesystem, opts vfs.SetStatOptions) error {
- stat := opts.Stat
- if stat.Mask&linux.STATX_MODE != 0 {
- return syserror.EPERM
- }
- return nil
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*taskInode) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
+ return syserror.EPERM
}
// taskOwnedInode implements kernfs.Inode and overrides inode owner with task
diff --git a/pkg/sentry/fsimpl/proc/tasks.go b/pkg/sentry/fsimpl/proc/tasks.go
index 07115664c..9f2ef8200 100644
--- a/pkg/sentry/fsimpl/proc/tasks.go
+++ b/pkg/sentry/fsimpl/proc/tasks.go
@@ -67,7 +67,7 @@ var _ kernfs.Inode = (*tasksInode)(nil)
func newTasksInode(inoGen InoGenerator, k *kernel.Kernel, pidns *kernel.PIDNamespace, cgroupControllers map[string]string) (*tasksInode, *kernfs.Dentry) {
root := auth.NewRootCredentials(pidns.UserNamespace())
contents := map[string]*kernfs.Dentry{
- "cpuinfo": newDentry(root, inoGen.NextIno(), 0444, newStaticFile(cpuInfoData(k))),
+ "cpuinfo": newDentry(root, inoGen.NextIno(), 0444, newStaticFileSetStat(cpuInfoData(k))),
"filesystems": newDentry(root, inoGen.NextIno(), 0444, &filesystemsData{}),
"loadavg": newDentry(root, inoGen.NextIno(), 0444, &loadavgData{}),
"sys": newSysDir(root, inoGen, k),
@@ -225,6 +225,20 @@ func (i *tasksInode) Stat(vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Sta
return stat, nil
}
+// staticFileSetStat implements a special static file that allows inode
+// attributes to be set. This is to support /proc files that are readonly, but
+// allow attributes to be set.
+type staticFileSetStat struct {
+ dynamicBytesFileSetAttr
+ vfs.StaticData
+}
+
+var _ dynamicInode = (*staticFileSetStat)(nil)
+
+func newStaticFileSetStat(data string) *staticFileSetStat {
+ return &staticFileSetStat{StaticData: vfs.StaticData{Data: data}}
+}
+
func cpuInfoData(k *kernel.Kernel) string {
features := k.FeatureSet()
if features == nil {
diff --git a/pkg/sentry/fsimpl/proc/tasks_files.go b/pkg/sentry/fsimpl/proc/tasks_files.go
index b99badba8..20085bb39 100644
--- a/pkg/sentry/fsimpl/proc/tasks_files.go
+++ b/pkg/sentry/fsimpl/proc/tasks_files.go
@@ -26,6 +26,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/kernel/time"
"gvisor.dev/gvisor/pkg/sentry/usage"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/usermem"
)
@@ -62,6 +63,11 @@ func (s *selfSymlink) Readlink(ctx context.Context) (string, error) {
return strconv.FormatUint(uint64(tgid), 10), nil
}
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*selfSymlink) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
+
type threadSelfSymlink struct {
kernfs.InodeAttrs
kernfs.InodeNoopRefCount
@@ -95,6 +101,23 @@ func (s *threadSelfSymlink) Readlink(ctx context.Context) (string, error) {
return fmt.Sprintf("%d/task/%d", tgid, tid), nil
}
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*threadSelfSymlink) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
+
+// dynamicBytesFileSetAttr implements a special file that allows inode
+// attributes to be set. This is to support /proc files that are readonly, but
+// allow attributes to be set.
+type dynamicBytesFileSetAttr struct {
+ kernfs.DynamicBytesFile
+}
+
+// SetStat implements Inode.SetStat.
+func (d *dynamicBytesFileSetAttr) SetStat(fs *vfs.Filesystem, opts vfs.SetStatOptions) error {
+ return d.DynamicBytesFile.InodeAttrs.SetStat(fs, opts)
+}
+
// cpuStats contains the breakdown of CPU time for /proc/stat.
type cpuStats struct {
// user is time spent in userspace tasks with non-positive niceness.
@@ -137,7 +160,7 @@ func (c cpuStats) String() string {
//
// +stateify savable
type statData struct {
- kernfs.DynamicBytesFile
+ dynamicBytesFileSetAttr
}
var _ dynamicInode = (*statData)(nil)
@@ -201,7 +224,7 @@ func (*statData) Generate(ctx context.Context, buf *bytes.Buffer) error {
//
// +stateify savable
type loadavgData struct {
- kernfs.DynamicBytesFile
+ dynamicBytesFileSetAttr
}
var _ dynamicInode = (*loadavgData)(nil)
@@ -220,7 +243,7 @@ func (*loadavgData) Generate(ctx context.Context, buf *bytes.Buffer) error {
//
// +stateify savable
type meminfoData struct {
- kernfs.DynamicBytesFile
+ dynamicBytesFileSetAttr
}
var _ dynamicInode = (*meminfoData)(nil)
@@ -271,7 +294,7 @@ func (*meminfoData) Generate(ctx context.Context, buf *bytes.Buffer) error {
//
// +stateify savable
type uptimeData struct {
- kernfs.DynamicBytesFile
+ dynamicBytesFileSetAttr
}
var _ dynamicInode = (*uptimeData)(nil)
@@ -290,7 +313,7 @@ func (*uptimeData) Generate(ctx context.Context, buf *bytes.Buffer) error {
//
// +stateify savable
type versionData struct {
- kernfs.DynamicBytesFile
+ dynamicBytesFileSetAttr
}
var _ dynamicInode = (*versionData)(nil)
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go
index c36c4fa11..3928ff2c8 100644
--- a/pkg/sentry/fsimpl/sys/sys.go
+++ b/pkg/sentry/fsimpl/sys/sys.go
@@ -94,15 +94,17 @@ func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, conte
return &d.dentry
}
-// SetStat implements kernfs.Inode.SetStat.
-func (d *dir) SetStat(fs *vfs.Filesystem, opts vfs.SetStatOptions) error {
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*dir) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
return syserror.EPERM
}
// Open implements kernfs.Inode.Open.
func (d *dir) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
fd := &kernfs.GenericDirectoryFD{}
- fd.Init(rp.Mount(), vfsd, &d.OrderedChildren, &opts)
+ if err := fd.Init(rp.Mount(), vfsd, &d.OrderedChildren, &opts); err != nil {
+ return nil, err
+ }
return fd.VFSFileDescription(), nil
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 23:01:00 +0000