On 07/13/2016 10:44 AM, Vivek Goyal wrote: > When a file is copied up in overlay, we have already created file on upper/ > with right label and there is no need to copy up selinux label/xattr from > lower file to upper file. In fact in case of context mount, we don't want > to copy up label as newly created file got its label from context= option. > > Signed-off-by: Vivek Goyal <[email protected]>
Acked-by: Stephen Smalley <[email protected]> > --- > security/selinux/hooks.c | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index c82ee54..4fda548 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -3290,6 +3290,21 @@ static int selinux_inode_copy_up(struct dentry *src, > struct cred **new) > return 0; > } > > +static int selinux_inode_copy_up_xattr(const char *name) > +{ > + /* The copy_up hook above sets the initial context on an inode, but we > + * don't then want to overwrite it by blindly copying all the lower > + * xattrs up. Instead, we have to filter out SELinux-related xattrs. > + */ > + if (strcmp(name, XATTR_NAME_SELINUX) == 0) > + return 1; /* Discard */ > + /* > + * Any other attribute apart from SELINUX is not claimed, supported > + * by selinux. > + */ > + return -EOPNOTSUPP; > +} > + > /* file security operations */ > > static int selinux_revalidate_file_permission(struct file *file, int mask) > @@ -6077,6 +6092,7 @@ static struct security_hook_list selinux_hooks[] = { > LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity), > LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid), > LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up), > + LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr), > > LSM_HOOK_INIT(file_permission, selinux_file_permission), > LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security), >
