scsi: lpfc: Use list_for_each_entry_safe() in rscn_recovery_check()

In GID_PT mode with lpfc_ns_query=1, a race condition between iterating the
vport->fc_nodes list in lpfc_rscn_recovery_check() and cleanup of an ndlp
can trigger a crash while processing the RSCN of another initiator from the
same zone.

During iteration of the vport->fc_nodes list, an ndlp is cleaned up and
released. lpfc_dequeue_node() is called from lpfc_cleanup_node() leading to
a bad ndlp dereference in lpfc_rscn_recovery_check().

Change list_for_each_entry() to list_for_each_entry_safe() in
lpfc_rscn_recovery_check() to protect against removal of an initiator ndlp,
while walking the vport->fc_nodes list.

Link: https://lore.kernel.org/r/20220506035519.50908-7-jsmart2021@gmail.com


Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>