4.4-stable review patch. If anyone has any objections, please let me know.
------------------ 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> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/infiniband/ulp/ipoib/ipoib_main.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/infiniband/ulp/ipoib/ipoib_main.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c @@ -1239,7 +1239,7 @@ static void __ipoib_reap_neigh(struct ip 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; @@ -1406,7 +1406,7 @@ void ipoib_neigh_free(struct ipoib_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 { @@ -1491,7 +1491,7 @@ void ipoib_del_neighs_by_gid(struct net_ 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; @@ -1533,7 +1533,7 @@ static void ipoib_flush_neighs(struct ip 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); } }