diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 04fa7337cb1e..35c97bc660bd 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -7089,6 +7089,12 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
 	ioc->pd_handles_sz = (ioc->facts.MaxDevHandle / 8);
 	if (ioc->facts.MaxDevHandle % 8)
 		ioc->pd_handles_sz++;
+	/*
+	 * pd_handles_sz should have, at least, the minimal room for
+	 * set_bit()/test_bit(), otherwise out-of-memory touch may occur.
+	 */
+	ioc->pd_handles_sz = ALIGN(ioc->pd_handles_sz, sizeof(unsigned long));
+
 	ioc->pd_handles = kzalloc(ioc->pd_handles_sz,
 	    GFP_KERNEL);
 	if (!ioc->pd_handles) {
@@ -7106,6 +7112,13 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
 	ioc->pend_os_device_add_sz = (ioc->facts.MaxDevHandle / 8);
 	if (ioc->facts.MaxDevHandle % 8)
 		ioc->pend_os_device_add_sz++;
+
+	/*
+	 * pend_os_device_add_sz should have, at least, the minimal room for
+	 * set_bit()/test_bit(), otherwise out-of-memory may occur.
+	 */
+	ioc->pend_os_device_add_sz = ALIGN(ioc->pend_os_device_add_sz,
+					   sizeof(unsigned long));
 	ioc->pend_os_device_add = kzalloc(ioc->pend_os_device_add_sz,
 	    GFP_KERNEL);
 	if (!ioc->pend_os_device_add) {
@@ -7384,6 +7397,12 @@ _base_check_ioc_facts_changes(struct MPT3SAS_ADAPTER *ioc)
 		if (ioc->facts.MaxDevHandle % 8)
 			pd_handles_sz++;
 
+		/*
+		 * pd_handles should have, at least, the minimal room for
+		 * set_bit()/test_bit(), otherwise out-of-memory touch may
+		 * occur.
+		 */
+		pd_handles_sz = ALIGN(pd_handles_sz, sizeof(unsigned long));
 		pd_handles = krealloc(ioc->pd_handles, pd_handles_sz,
 		    GFP_KERNEL);
 		if (!pd_handles) {