net/rds: Fix error handling in rds_ib_add_one()

BugLink: https://bugs.launchpad.net/bugs/1848598

[ Upstream commit d64bf89a ]

rds_ibdev:ipaddr_list and rds_ibdev:conn_list are initialized
after allocation some resources such as protection domain.
If allocation of such resources fail, then these uninitialized
variables are accessed in rds_ib_dev_free() in failure path. This
can potentially crash the system. The code has been updated to
initialize these variables very early in the function.
Signed-off-by: Dotan Barak <dotanb@dev.mellanox.co.il>
Signed-off-by: Sudhakar Dindukurti <sudhakar.dindukurti@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

net/rds/ib.c

@@ -146,6 +146,9 @@ static void rds_ib_add_one(struct ib_device *device)
 	atomic_set(&rds_ibdev->refcount, 1);
 	INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);
 
+	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
+	INIT_LIST_HEAD(&rds_ibdev->conn_list);
+
 	rds_ibdev->max_wrs = dev_attr->max_qp_wr;
 	rds_ibdev->max_sge = min(dev_attr->max_sge, RDS_IB_MAX_SGE);
 
@@ -187,9 +190,6 @@ static void rds_ib_add_one(struct ib_device *device)
 		 rds_ibdev->fmr_max_remaps, rds_ibdev->max_1m_fmrs,
 		 rds_ibdev->max_8k_fmrs);
 
-	INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
-	INIT_LIST_HEAD(&rds_ibdev->conn_list);
-
 	down_write(&rds_ib_devices_lock);
 	list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
 	up_write(&rds_ib_devices_lock);