From 7a45ae7e67438697296fc12345202e3c76304096 Mon Sep 17 00:00:00 2001 From: Dean Deng Date: Thu, 16 Jan 2020 18:13:27 -0800 Subject: Implement setxattr for overlays. PiperOrigin-RevId: 290186303 --- pkg/sentry/fs/inode.go | 4 ++-- pkg/sentry/fs/inode_overlay.go | 13 ++++++++++--- pkg/sentry/syscalls/linux/sys_xattr.go | 2 +- 3 files changed, 13 insertions(+), 6 deletions(-) (limited to 'pkg') diff --git a/pkg/sentry/fs/inode.go b/pkg/sentry/fs/inode.go index ee9d301ef..e4cf5a570 100644 --- a/pkg/sentry/fs/inode.go +++ b/pkg/sentry/fs/inode.go @@ -270,9 +270,9 @@ func (i *Inode) GetXattr(ctx context.Context, name string, size uint64) (string, } // SetXattr calls i.InodeOperations.SetXattr with i as the Inode. -func (i *Inode) SetXattr(ctx context.Context, name, value string, flags uint32) error { +func (i *Inode) SetXattr(ctx context.Context, d *Dirent, name, value string, flags uint32) error { if i.overlay != nil { - return overlaySetxattr(ctx, i.overlay, name, value, flags) + return overlaySetxattr(ctx, i.overlay, d, name, value, flags) } return i.InodeOperations.SetXattr(ctx, i, name, value, flags) } diff --git a/pkg/sentry/fs/inode_overlay.go b/pkg/sentry/fs/inode_overlay.go index b90da20d0..c477de837 100644 --- a/pkg/sentry/fs/inode_overlay.go +++ b/pkg/sentry/fs/inode_overlay.go @@ -552,9 +552,16 @@ func overlayGetXattr(ctx context.Context, o *overlayEntry, name string, size uin return s, err } -// TODO(b/146028302): Support setxattr for overlayfs. -func overlaySetxattr(ctx context.Context, o *overlayEntry, name, value string, flags uint32) error { - return syserror.EOPNOTSUPP +func overlaySetxattr(ctx context.Context, o *overlayEntry, d *Dirent, name, value string, flags uint32) error { + // Don't allow changes to overlay xattrs through a setxattr syscall. + if strings.HasPrefix(XattrOverlayPrefix, name) { + return syserror.EPERM + } + + if err := copyUp(ctx, d); err != nil { + return err + } + return o.upper.SetXattr(ctx, d, name, value, flags) } func overlayListXattr(ctx context.Context, o *overlayEntry) (map[string]struct{}, error) { diff --git a/pkg/sentry/syscalls/linux/sys_xattr.go b/pkg/sentry/syscalls/linux/sys_xattr.go index 816352218..23d20da6f 100644 --- a/pkg/sentry/syscalls/linux/sys_xattr.go +++ b/pkg/sentry/syscalls/linux/sys_xattr.go @@ -142,7 +142,7 @@ func setXattr(t *kernel.Task, d *fs.Dirent, dirPath bool, nameAddr, valueAddr us return syserror.EOPNOTSUPP } - return d.Inode.SetXattr(t, name, value, flags) + return d.Inode.SetXattr(t, d, name, value, flags) } func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) { -- cgit v1.2.3