On Wed, Jan 9, 2019 at 9:38 AM Stephen Smalley [off-list ref] wrote:

On 1/9/19 4:10 AM, Ondrej Mosnacek wrote:

quoted

The hook applies the same logic as selinux_determine_inode_label(), with
the exception of the super_block handling, which will be enforced on the
actual inodes by other hooks.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>

Reviewed-by: Stephen Smalley <redacted>

Looks good to me too.

quoted

---
  security/selinux/hooks.c | 41 ++++++++++++++++++++++++++++++++++++++++
  1 file changed, 41 insertions(+)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7ce012d9ec51..29c038513504 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c

@@ -3526,6 +3526,45 @@ static int selinux_inode_copy_up_xattr(const char *name)
      return -EOPNOTSUPP;
  }

+/* file-like object operations */
+
+/* Used e.g. for kernfs_node for newly created nodes */
+static int selinux_object_init_security(void *parent_ctx, u32 parent_ctxlen,
+                                     const struct qstr *qstr, u16 mode,
+                                     void **ctx, u32 *ctxlen)
+{
+     const struct task_security_struct *tsec = current_security();
+     u32 parent_sid, newsid, clen;
+     int rc;
+     char *context;
+
+     rc = security_context_to_sid(&selinux_state, parent_ctx, parent_ctxlen,
+                                  &parent_sid, GFP_KERNEL);
+     if (rc)
+             return rc;
+
+     if (tsec->create_sid) {
+             newsid = tsec->create_sid;
+     } else {
+             u16 secclass = inode_mode_to_security_class(mode);
+
+             rc = security_transition_sid(&selinux_state, tsec->sid,
+                                          parent_sid, secclass, qstr,
+                                          &newsid);
+             if (rc)
+                     return rc;
+     }
+
+     rc = security_sid_to_context_force(&selinux_state, newsid,
+                                        &context, &clen);
+     if (rc)
+             return rc;
+
+     *ctx = context;
+     *ctxlen = clen;
+     return 0;
+}
+
  /* file security operations */

  static int selinux_revalidate_file_permission(struct file *file, int mask)

@@ -6965,6 +7004,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
      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(object_init_security, selinux_object_init_security),
+
      LSM_HOOK_INIT(file_permission, selinux_file_permission),
      LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
      LSM_HOOK_INIT(file_free_security, selinux_file_free_security),

-- 
paul moore
www.paul-moore.com