From 9a90400821c9df5131b8e3ab84a2575ec8c25bba Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Thu, 12 Jul 2018 10:21:49 -0700
Subject: [PATCH] agent/checks: prevent overflow of backoff

---
 agent/checks/alias.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/agent/checks/alias.go b/agent/checks/alias.go
index 5a40693c54..e6c7082e57 100644
--- a/agent/checks/alias.go
+++ b/agent/checks/alias.go
@@ -120,7 +120,11 @@ func (c *CheckAlias) runQuery(stopCh chan struct{}) {
 
 		// Backoff if we have to
 		if attempt > checkAliasBackoffMin {
-			waitTime := (1 << (attempt - checkAliasBackoffMin)) * time.Second
+			shift := attempt - checkAliasBackoffMin
+			if shift > 31 {
+				shift = 31 // so we don't overflow to 0
+			}
+			waitTime := (1 << shift) * time.Second
 			if waitTime > checkAliasBackoffMaxWait {
 				waitTime = checkAliasBackoffMaxWait
 			}