Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

[karo-tx-linux.git] / security / keys / keyctl.c

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 21907ea35b15c118515eb03dea87efab7f8ad9f8..0f5b3f0272995dc7057f1306c346468174d3e464 100644 (file)
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1454,50 +1454,57 @@ long keyctl_get_security(key_serial_t keyid,
  */
 long keyctl_session_to_parent(void)
 {
-#ifdef TIF_NOTIFY_RESUME
        struct task_struct *me, *parent;
        const struct cred *mycred, *pcred;
-       struct cred *cred, *oldcred;
+       struct task_work *newwork, *oldwork;
        key_ref_t keyring_r;
+       struct cred *cred;
        int ret;
 
        keyring_r = lookup_user_key(KEY_SPEC_SESSION_KEYRING, 0, KEY_LINK);
        if (IS_ERR(keyring_r))
                return PTR_ERR(keyring_r);
 
+       ret = -ENOMEM;
+       newwork = kmalloc(sizeof(struct task_work), GFP_KERNEL);
+       if (!newwork)
+               goto error_keyring;
+
        /* our parent is going to need a new cred struct, a new tgcred struct
         * and new security data, so we allocate them here to prevent ENOMEM in
         * our parent */
-       ret = -ENOMEM;
        cred = cred_alloc_blank();
        if (!cred)
-               goto error_keyring;
+               goto error_newwork;
 
        cred->tgcred->session_keyring = key_ref_to_ptr(keyring_r);
-       keyring_r = NULL;
+       init_task_work(newwork, key_change_session_keyring, cred);
 
        me = current;
        rcu_read_lock();
        write_lock_irq(&tasklist_lock);
 
-       parent = me->real_parent;
        ret = -EPERM;
+       oldwork = NULL;
+       parent = me->real_parent;
 
        /* the parent mustn't be init and mustn't be a kernel thread */
        if (parent->pid <= 1 || !parent->mm)
-               goto not_permitted;
+               goto unlock;
 
        /* the parent must be single threaded */
        if (!thread_group_empty(parent))
-               goto not_permitted;
+               goto unlock;
 
        /* the parent and the child must have different session keyrings or
         * there's no point */
        mycred = current_cred();
        pcred = __task_cred(parent);
        if (mycred == pcred ||
-           mycred->tgcred->session_keyring == pcred->tgcred->session_keyring)
-               goto already_same;
+           mycred->tgcred->session_keyring == pcred->tgcred->session_keyring) {
+               ret = 0;
+               goto unlock;
+       }
 
        /* the parent must have the same effective ownership and mustn't be
         * SUID/SGID */
@@ -1507,50 +1514,40 @@ long keyctl_session_to_parent(void)
            pcred->gid  != mycred->egid ||
            pcred->egid != mycred->egid ||
            pcred->sgid != mycred->egid)
-               goto not_permitted;
+               goto unlock;
 
        /* the keyrings must have the same UID */
        if ((pcred->tgcred->session_keyring &&
             pcred->tgcred->session_keyring->uid != mycred->euid) ||
            mycred->tgcred->session_keyring->uid != mycred->euid)
-               goto not_permitted;
+               goto unlock;
 
-       /* if there's an already pending keyring replacement, then we replace
-        * that */
-       oldcred = parent->replacement_session_keyring;
+       /* cancel an already pending keyring replacement */
+       oldwork = task_work_cancel(parent, key_change_session_keyring);
 
        /* the replacement session keyring is applied just prior to userspace
         * restarting */
-       parent->replacement_session_keyring = cred;
-       cred = NULL;
-       set_ti_thread_flag(task_thread_info(parent), TIF_NOTIFY_RESUME);
-
+       ret = task_work_add(parent, newwork, true);
+       if (!ret)
+               newwork = NULL;
+unlock:
        write_unlock_irq(&tasklist_lock);
        rcu_read_unlock();
-       if (oldcred)
-               put_cred(oldcred);
-       return 0;
-
-already_same:
-       ret = 0;
-not_permitted:
-       write_unlock_irq(&tasklist_lock);
-       rcu_read_unlock();
-       put_cred(cred);
+       if (oldwork) {
+               put_cred(oldwork->data);
+               kfree(oldwork);
+       }
+       if (newwork) {
+               put_cred(newwork->data);
+               kfree(newwork);
+       }
        return ret;
 
+error_newwork:
+       kfree(newwork);
 error_keyring:
        key_ref_put(keyring_r);
        return ret;
-
-#else /* !TIF_NOTIFY_RESUME */
-       /*
-        * To be removed when TIF_NOTIFY_RESUME has been implemented on
-        * m68k/xtensa
-        */
-#warning TIF_NOTIFY_RESUME not implemented
-       return -EOPNOTSUPP;
-#endif /* !TIF_NOTIFY_RESUME */
 }
 
 /*