audit: Call tty_audit_push_task() outside preempt disabled

[cascardo/linux.git] / drivers / char / tty_audit.c

diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c
index 1b8ee59..f64582b 100644 (file)
--- a/drivers/char/tty_audit.c
+++ b/drivers/char/tty_audit.c
@@ -188,25 +188,43 @@ void tty_audit_tiocsti(struct tty_struct *tty, char ch)
 }
 
 /**
- *     tty_audit_push_task     -       Flush task's pending audit data
+ * tty_audit_push_task -       Flush task's pending audit data
+ * @tsk:               task pointer
+ * @loginuid:          sender login uid
+ * @sessionid:         sender session id
+ *
+ * Called with a ref on @tsk held. Try to lock sighand and get a
+ * reference to the tty audit buffer if available.
+ * Flush the buffer or return an appropriate error code.
  */
-void tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
+int tty_audit_push_task(struct task_struct *tsk, uid_t loginuid, u32 sessionid)
 {
-       struct tty_audit_buf *buf;
+       struct tty_audit_buf *buf = ERR_PTR(-EPERM);
+       unsigned long flags;
 
-       spin_lock_irq(&tsk->sighand->siglock);
-       buf = tsk->signal->tty_audit_buf;
-       if (buf)
-               atomic_inc(&buf->count);
-       spin_unlock_irq(&tsk->sighand->siglock);
-       if (!buf)
-               return;
+       if (!lock_task_sighand(tsk, &flags))
+               return -ESRCH;
+
+       if (tsk->signal->audit_tty) {
+               buf = tsk->signal->tty_audit_buf;
+               if (buf)
+                       atomic_inc(&buf->count);
+       }
+       unlock_task_sighand(tsk, &flags);
+
+       /*
+        * Return 0 when signal->audit_tty set
+        * but tsk->signal->tty_audit_buf == NULL.
+        */
+       if (!buf || IS_ERR(buf))
+               return PTR_ERR(buf);
 
        mutex_lock(&buf->mutex);
        tty_audit_buf_push(tsk, loginuid, sessionid, buf);
        mutex_unlock(&buf->mutex);
 
        tty_audit_buf_put(buf);
+       return 0;
 }
 
 /**