1 files changed, 16 insertions, 1 deletions

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 6261745e4459..639226afd0db 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1091,7 +1091,7 @@ error:
 long keyctl_set_timeout(key_serial_t id, unsigned timeout)
 {
         struct timespec now;
-        struct key *key;
+        struct key *key, *instkey;
         key_ref_t key_ref;
         time_t expiry;
         long ret;
@@ -1099,10 +1099,25 @@ long keyctl_set_timeout(key_serial_t id, unsigned timeout)
         key_ref = lookup_user_key(id, KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL,
                                   KEY_SETATTR);
         if (IS_ERR(key_ref)) {
+                /* setting the timeout on a key under construction is permitted
+                 * if we have the authorisation token handy */
+                if (PTR_ERR(key_ref) == -EACCES) {
+                        instkey = key_get_instantiation_authkey(id);
+                        if (!IS_ERR(instkey)) {
+                                key_put(instkey);
+                                key_ref = lookup_user_key(id,
+                                                          KEY_LOOKUP_PARTIAL,
+                                                          0);
+                                if (!IS_ERR(key_ref))
+                                        goto okay;
+                        }
+                }
+
                 ret = PTR_ERR(key_ref);
                 goto error;
         }
 
+okay:
         key = key_ref_to_ptr(key_ref);
 
         /* make the changes with the locks held to prevent races */