From: Feras Daoud <fera...@mellanox.com>

[ Upstream commit c586071d1dc8227a7182179b8e50ee92cc43f6d2 ]

In order to resolve a situation where a few process delete
the same list element in sequence and cause panic, list_del
is replaced with list_del_init. In this case if the first
process that calls list_del releases the lock before acquiring
it again, other processes who can acquire the lock will call
list_del_init.

Fixes: b63b70d87741 ("IPoIB: Use a private hash table for path lookup")
Signed-off-by: Feras Daoud <fera...@mellanox.com>
Signed-off-by: Erez Shitrit <ere...@mellanox.com>
Reviewed-by: Alex Vesker <va...@mellanox.com>
Signed-off-by: Leon Romanovsky <l...@kernel.org>
Reviewed-by: Yuval Shaia <yuval.sh...@oracle.com>
Signed-off-by: Doug Ledford <dledf...@redhat.com>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
---
 drivers/infiniband/ulp/ipoib/ipoib_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c 
b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 5e08db6f9d8c..eab9eda0e7bd 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -958,7 +958,7 @@ static void __ipoib_reap_neigh(struct ipoib_dev_priv *priv)
                                                   
rcu_dereference_protected(neigh->hnext,
                                                                             
lockdep_is_held(&priv->lock)));
                                /* remove from path/mc list */
-                               list_del(&neigh->list);
+                               list_del_init(&neigh->list);
                                call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                        } else {
                                np = &neigh->hnext;
@@ -1121,7 +1121,7 @@ void ipoib_neigh_free(struct ipoib_neigh *neigh)
                                           
rcu_dereference_protected(neigh->hnext,
                                                                     
lockdep_is_held(&priv->lock)));
                        /* remove from parent list */
-                       list_del(&neigh->list);
+                       list_del_init(&neigh->list);
                        call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                        return;
                } else {
@@ -1206,7 +1206,7 @@ void ipoib_del_neighs_by_gid(struct net_device *dev, u8 
*gid)
                                                   
rcu_dereference_protected(neigh->hnext,
                                                                             
lockdep_is_held(&priv->lock)));
                                /* remove from parent list */
-                               list_del(&neigh->list);
+                               list_del_init(&neigh->list);
                                call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                        } else {
                                np = &neigh->hnext;
@@ -1248,7 +1248,7 @@ static void ipoib_flush_neighs(struct ipoib_dev_priv 
*priv)
                                           
rcu_dereference_protected(neigh->hnext,
                                                                     
lockdep_is_held(&priv->lock)));
                        /* remove from path/mc list */
-                       list_del(&neigh->list);
+                       list_del_init(&neigh->list);
                        call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                }
        }
-- 
2.11.0

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