[PATCH] mpt3sas:Fix kernel panic during drive powercycle test

From: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
To: linux-scsi@vger.kernel.org, martin.petersen@oracle.com
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Subject: [PATCH] mpt3sas:Fix kernel panic during drive powercycle test
Date: Wed, 17 Nov 2021 16:19:09 +0530	[thread overview]
Message-ID: <20211117104909.2069-1-sreekanth.reddy@broadcom.com> (raw)

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While looping over shost's sdev list it is possible that one
of the drive is getting removed and it's sas_target object is
freed but it's sdev object is still intact with the sdev list.
So, kernel panic occurred while driver trying to access the sas_address
field of sas_target object without checking the sas_target object
for NULL pointer.

Fixes: f92363d12359("mpt3sas: add new driver supporting 12GB SAS")
Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
---
 drivers/scsi/mpt3sas/mpt3sas_scsih.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index cee7170beae8..bb0036b41825 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -3869,7 +3869,7 @@ _scsih_ublock_io_device(struct MPT3SAS_ADAPTER *ioc,
 
 	shost_for_each_device(sdev, ioc->shost) {
 		sas_device_priv_data = sdev->hostdata;
-		if (!sas_device_priv_data)
+		if (!sas_device_priv_data || !sas_device_priv_data->sas_target)
 			continue;
 		if (sas_device_priv_data->sas_target->sas_address
 		    != sas_address)
-- 
2.27.0


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