[PATCH AUTOSEL for 4.9 42/50] IB/ipoib: Change list_del to list_del_init in the tx object

[Levin, Alexander (Sasha Levin)]

From: Feras Daoud <ferasda@xxxxxxxxxxxx>

[ Upstream commit 27d41d29c7f093f6f77843624fbb080c1b4a8b9c ]

Since ipoib_cm_tx_start function and ipoib_cm_tx_reap function
belong to different work queues, they can run in parallel.
In this case if ipoib_cm_tx_reap calls list_del and release the
lock, ipoib_cm_tx_start may acquire it and call list_del_init
on the already deleted object.
Changing list_del to list_del_init in ipoib_cm_tx_reap fixes the problem.

Fixes: 839fcaba355a ("IPoIB: Connected mode experimental support")
Signed-off-by: Feras Daoud <ferasda@xxxxxxxxxxxx>
Signed-off-by: Erez Shitrit <erezsh@xxxxxxxxxxxx>
Reviewed-by: Alex Vesker <valex@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
Reviewed-by: Yuval Shaia <yuval.shaia@xxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
 drivers/infiniband/ulp/ipoib/ipoib_cm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 0616a65f0d78..75761667be59 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -1392,7 +1392,7 @@ static void ipoib_cm_tx_reap(struct work_struct *work)
 
 	while (!list_empty(&priv->cm.reap_list)) {
 		p = list_entry(priv->cm.reap_list.next, typeof(*p), list);
-		list_del(&p->list);
+		list_del_init(&p->list);
 		spin_unlock_irqrestore(&priv->lock, flags);
 		netif_tx_unlock_bh(dev);
 		ipoib_cm_tx_destroy(p);
-- 
2.11.0