[PATCH] mpt3sas: fix an out of bound write

[Tomas Henzl]

cpu_msix_table is allocated to store online cpus, but pci_irq_get_affinity
may return cpu_possible_mask which is then used to access cpu_msix_table.
That causes bad user experience.
Fix limits access to only online cpus, I've also added an additonal test
to protect from an unlikely change in cpu_online_mask.

Fixes: 1d55abc0e98a0bf35f3af80665aac564e3b30572 scsi: mpt3sas: switch to 
pci_alloc_irq_vectors

Signed-off-by: Tomas Henzl <the...@redhat.com>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c 
b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 13d6e4ec3..59a87ca32 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -2410,8 +2410,11 @@ _base_assign_reply_queues(struct MPT3SAS_ADAPTER *ioc)
                                continue;
                        }
 
-                       for_each_cpu(cpu, mask)
+                       for_each_cpu_and(cpu, mask, cpu_online_mask) {
+                               if (cpu >= ioc->cpu_msix_table_sz)
+                                       break;
                                ioc->cpu_msix_table[cpu] = reply_q->msix_index;
+                       }
                }
                return;
        }
-- 
2.14.3