diff options
Diffstat (limited to 'pkg/sentry/fsimpl')
-rw-r--r-- | pkg/sentry/fsimpl/proc/proc_state_autogen.go | 78 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/proc/task.go | 1 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/proc/task_files.go | 157 |
3 files changed, 236 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/proc/proc_state_autogen.go b/pkg/sentry/fsimpl/proc/proc_state_autogen.go index 1b5e98012..f2ba64a7f 100644 --- a/pkg/sentry/fsimpl/proc/proc_state_autogen.go +++ b/pkg/sentry/fsimpl/proc/proc_state_autogen.go @@ -672,6 +672,82 @@ func (d *idMapData) StateLoad(stateSourceObject state.Source) { stateSourceObject.Load(2, &d.gids) } +func (f *memInode) StateTypeName() string { + return "pkg/sentry/fsimpl/proc.memInode" +} + +func (f *memInode) StateFields() []string { + return []string{ + "InodeAttrs", + "InodeNoStatFS", + "InodeNoopRefCount", + "InodeNotDirectory", + "InodeNotSymlink", + "task", + "locks", + } +} + +func (f *memInode) beforeSave() {} + +func (f *memInode) StateSave(stateSinkObject state.Sink) { + f.beforeSave() + stateSinkObject.Save(0, &f.InodeAttrs) + stateSinkObject.Save(1, &f.InodeNoStatFS) + stateSinkObject.Save(2, &f.InodeNoopRefCount) + stateSinkObject.Save(3, &f.InodeNotDirectory) + stateSinkObject.Save(4, &f.InodeNotSymlink) + stateSinkObject.Save(5, &f.task) + stateSinkObject.Save(6, &f.locks) +} + +func (f *memInode) afterLoad() {} + +func (f *memInode) StateLoad(stateSourceObject state.Source) { + stateSourceObject.Load(0, &f.InodeAttrs) + stateSourceObject.Load(1, &f.InodeNoStatFS) + stateSourceObject.Load(2, &f.InodeNoopRefCount) + stateSourceObject.Load(3, &f.InodeNotDirectory) + stateSourceObject.Load(4, &f.InodeNotSymlink) + stateSourceObject.Load(5, &f.task) + stateSourceObject.Load(6, &f.locks) +} + +func (fd *memFD) StateTypeName() string { + return "pkg/sentry/fsimpl/proc.memFD" +} + +func (fd *memFD) StateFields() []string { + return []string{ + "vfsfd", + "FileDescriptionDefaultImpl", + "LockFD", + "inode", + "offset", + } +} + +func (fd *memFD) beforeSave() {} + +func (fd *memFD) StateSave(stateSinkObject state.Sink) { + fd.beforeSave() + stateSinkObject.Save(0, &fd.vfsfd) + stateSinkObject.Save(1, &fd.FileDescriptionDefaultImpl) + stateSinkObject.Save(2, &fd.LockFD) + stateSinkObject.Save(3, &fd.inode) + stateSinkObject.Save(4, &fd.offset) +} + +func (fd *memFD) afterLoad() {} + +func (fd *memFD) StateLoad(stateSourceObject state.Source) { + stateSourceObject.Load(0, &fd.vfsfd) + stateSourceObject.Load(1, &fd.FileDescriptionDefaultImpl) + stateSourceObject.Load(2, &fd.LockFD) + stateSourceObject.Load(3, &fd.inode) + stateSourceObject.Load(4, &fd.offset) +} + func (d *mapsData) StateTypeName() string { return "pkg/sentry/fsimpl/proc.mapsData" } @@ -1941,6 +2017,8 @@ func init() { state.Register((*commInode)(nil)) state.Register((*commData)(nil)) state.Register((*idMapData)(nil)) + state.Register((*memInode)(nil)) + state.Register((*memFD)(nil)) state.Register((*mapsData)(nil)) state.Register((*smapsData)(nil)) state.Register((*taskStatData)(nil)) diff --git a/pkg/sentry/fsimpl/proc/task.go b/pkg/sentry/fsimpl/proc/task.go index 57cf8ce26..19011b010 100644 --- a/pkg/sentry/fsimpl/proc/task.go +++ b/pkg/sentry/fsimpl/proc/task.go @@ -64,6 +64,7 @@ func (fs *filesystem) newTaskInode(task *kernel.Task, pidns *kernel.PIDNamespace "gid_map": fs.newTaskOwnedInode(task, fs.NextIno(), 0644, &idMapData{task: task, gids: true}), "io": fs.newTaskOwnedInode(task, fs.NextIno(), 0400, newIO(task, isThreadGroup)), "maps": fs.newTaskOwnedInode(task, fs.NextIno(), 0444, &mapsData{task: task}), + "mem": fs.newMemInode(task, fs.NextIno(), 0400), "mountinfo": fs.newTaskOwnedInode(task, fs.NextIno(), 0444, &mountInfoData{task: task}), "mounts": fs.newTaskOwnedInode(task, fs.NextIno(), 0444, &mountsData{task: task}), "net": fs.newTaskNetDir(task), diff --git a/pkg/sentry/fsimpl/proc/task_files.go b/pkg/sentry/fsimpl/proc/task_files.go index d3f4e259b..ba71d0fde 100644 --- a/pkg/sentry/fsimpl/proc/task_files.go +++ b/pkg/sentry/fsimpl/proc/task_files.go @@ -31,6 +31,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/mm" "gvisor.dev/gvisor/pkg/sentry/usage" "gvisor.dev/gvisor/pkg/sentry/vfs" + "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/syserror" "gvisor.dev/gvisor/pkg/usermem" ) @@ -366,6 +367,162 @@ func (d *idMapData) Write(ctx context.Context, src usermem.IOSequence, offset in return int64(srclen), nil } +var _ kernfs.Inode = (*memInode)(nil) + +// memInode implements kernfs.Inode for /proc/[pid]/mem. +// +// +stateify savable +type memInode struct { + kernfs.InodeAttrs + kernfs.InodeNoStatFS + kernfs.InodeNoopRefCount + kernfs.InodeNotDirectory + kernfs.InodeNotSymlink + + task *kernel.Task + locks vfs.FileLocks +} + +func (fs *filesystem) newMemInode(task *kernel.Task, ino uint64, perm linux.FileMode) kernfs.Inode { + // Note: credentials are overridden by taskOwnedInode. + inode := &memInode{task: task} + inode.init(task, task.Credentials(), linux.UNNAMED_MAJOR, fs.devMinor, ino, perm) + return &taskOwnedInode{Inode: inode, owner: task} +} + +func (f *memInode) init(ctx context.Context, creds *auth.Credentials, devMajor, devMinor uint32, ino uint64, perm linux.FileMode) { + if perm&^linux.PermissionsMask != 0 { + panic(fmt.Sprintf("Only permission mask must be set: %x", perm&linux.PermissionsMask)) + } + f.InodeAttrs.Init(ctx, creds, devMajor, devMinor, ino, linux.ModeRegular|perm) +} + +// Open implements kernfs.Inode.Open. +func (f *memInode) Open(ctx context.Context, rp *vfs.ResolvingPath, d *kernfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) { + // TODO(gvisor.dev/issue/260): Add check for PTRACE_MODE_ATTACH_FSCREDS + // Permission to read this file is governed by PTRACE_MODE_ATTACH_FSCREDS + // Since we dont implement setfsuid/setfsgid we can just use PTRACE_MODE_ATTACH + if !kernel.ContextCanTrace(ctx, f.task, true) { + return nil, syserror.EACCES + } + if err := checkTaskState(f.task); err != nil { + return nil, err + } + fd := &memFD{} + if err := fd.Init(rp.Mount(), d, f, opts.Flags); err != nil { + return nil, err + } + return &fd.vfsfd, nil +} + +// SetStat implements kernfs.Inode.SetStat. +func (*memInode) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error { + return syserror.EPERM +} + +var _ vfs.FileDescriptionImpl = (*memFD)(nil) + +// memFD implements vfs.FileDescriptionImpl for /proc/[pid]/mem. +// +// +stateify savable +type memFD struct { + vfsfd vfs.FileDescription + vfs.FileDescriptionDefaultImpl + vfs.LockFD + + inode *memInode + + // mu guards the fields below. + mu sync.Mutex `state:"nosave"` + offset int64 +} + +// Init initializes memFD. +func (fd *memFD) Init(m *vfs.Mount, d *kernfs.Dentry, inode *memInode, flags uint32) error { + fd.LockFD.Init(&inode.locks) + if err := fd.vfsfd.Init(fd, flags, m, d.VFSDentry(), &vfs.FileDescriptionOptions{}); err != nil { + return err + } + fd.inode = inode + return nil +} + +// Seek implements vfs.FileDescriptionImpl.Seek. +func (fd *memFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) { + fd.mu.Lock() + defer fd.mu.Unlock() + switch whence { + case linux.SEEK_SET: + case linux.SEEK_CUR: + offset += fd.offset + default: + return 0, syserror.EINVAL + } + if offset < 0 { + return 0, syserror.EINVAL + } + fd.offset = offset + return offset, nil +} + +// PRead implements vfs.FileDescriptionImpl.PRead. +func (fd *memFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) { + if dst.NumBytes() == 0 { + return 0, nil + } + m, err := getMMIncRef(fd.inode.task) + if err != nil { + return 0, nil + } + defer m.DecUsers(ctx) + // Buffer the read data because of MM locks + buf := make([]byte, dst.NumBytes()) + n, readErr := m.CopyIn(ctx, usermem.Addr(offset), buf, usermem.IOOpts{IgnorePermissions: true}) + if n > 0 { + if _, err := dst.CopyOut(ctx, buf[:n]); err != nil { + return 0, syserror.EFAULT + } + return int64(n), nil + } + if readErr != nil { + return 0, syserror.EIO + } + return 0, nil +} + +// Read implements vfs.FileDescriptionImpl.Read. +func (fd *memFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) { + fd.mu.Lock() + n, err := fd.PRead(ctx, dst, fd.offset, opts) + fd.offset += n + fd.mu.Unlock() + return n, err +} + +// Stat implements vfs.FileDescriptionImpl.Stat. +func (fd *memFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) { + fs := fd.vfsfd.VirtualDentry().Mount().Filesystem() + return fd.inode.Stat(ctx, fs, opts) +} + +// SetStat implements vfs.FileDescriptionImpl.SetStat. +func (fd *memFD) SetStat(context.Context, vfs.SetStatOptions) error { + return syserror.EPERM +} + +// Release implements vfs.FileDescriptionImpl.Release. +func (fd *memFD) Release(context.Context) {} + +// LockPOSIX implements vfs.FileDescriptionImpl.LockPOSIX. +func (fd *memFD) LockPOSIX(ctx context.Context, uid fslock.UniqueID, t fslock.LockType, start, length uint64, whence int16, block fslock.Blocker) error { + return fd.Locks().LockPOSIX(ctx, &fd.vfsfd, uid, t, start, length, whence, block) +} + +// UnlockPOSIX implements vfs.FileDescriptionImpl.UnlockPOSIX. +func (fd *memFD) UnlockPOSIX(ctx context.Context, uid fslock.UniqueID, start, length uint64, whence int16) error { + return fd.Locks().UnlockPOSIX(ctx, &fd.vfsfd, uid, start, length, whence) +} + // mapsData implements vfs.DynamicBytesSource for /proc/[pid]/maps. // // +stateify savable |