From: Preethi Banala <preethi.banala@intel.com>
Date: Thu, 9 Aug 2018 06:28:55 -0700
Subject: ice: Clean control queues only when they are initialized
Patch-mainline: v4.19-rc2
Git-commit: b29bc220e2c7bd494a4605defcd93b18d5a8cf86
References: bsc#1118661 FATE#325277

Clean control queues only when they are initialized. One of the ways to
validate if the basic initialization is done is by checking value of
cq->sq.head and cq->rq.head variables that specify the register address.
This patch adds a check to avoid NULL pointer dereference crash when tried
to shutdown uninitialized control queue.

Signed-off-by: Preethi Banala <preethi.banala@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/ice/ice_controlq.c |   24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

--- a/drivers/net/ethernet/intel/ice/ice_controlq.c
+++ b/drivers/net/ethernet/intel/ice/ice_controlq.c
@@ -597,10 +597,14 @@ static enum ice_status ice_init_check_ad
 	return 0;
 
 init_ctrlq_free_rq:
-	ice_shutdown_rq(hw, cq);
-	ice_shutdown_sq(hw, cq);
-	mutex_destroy(&cq->sq_lock);
-	mutex_destroy(&cq->rq_lock);
+	if (cq->rq.head) {
+		ice_shutdown_rq(hw, cq);
+		mutex_destroy(&cq->rq_lock);
+	}
+	if (cq->sq.head) {
+		ice_shutdown_sq(hw, cq);
+		mutex_destroy(&cq->sq_lock);
+	}
 	return status;
 }
 
@@ -706,10 +710,14 @@ static void ice_shutdown_ctrlq(struct ic
 		return;
 	}
 
-	ice_shutdown_sq(hw, cq);
-	ice_shutdown_rq(hw, cq);
-	mutex_destroy(&cq->sq_lock);
-	mutex_destroy(&cq->rq_lock);
+	if (cq->sq.head) {
+		ice_shutdown_sq(hw, cq);
+		mutex_destroy(&cq->sq_lock);
+	}
+	if (cq->rq.head) {
+		ice_shutdown_rq(hw, cq);
+		mutex_destroy(&cq->rq_lock);
+	}
 }
 
 /**