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Commit 63e359d4 authored by Sreekanth Reddy's avatar Sreekanth Reddy Committed by James Bottomley
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[SCSI] mpt2sas: Fix for kernel panic when driver loads with HBA connected to... 


[SCSI] mpt2sas: Fix for kernel panic when driver loads with HBA connected to non LUN 0 configured expander

With some enclosures when LUN 0 is not created but LUN 1 or LUN X is created
then SCSI scan procedure calls target_alloc, slave_alloc call back functions
for LUN 0 and slave_destory() for same LUN 0.

In these kind of cases within slave_destroy, pointer to scsi_target in
_sas_device structure is set to NULL, following which when slave_alloc for
LUN 1 is called then starget would not be set properly for this LUN.
So, scsi_target pointer pointing to NULL value would lead to a crash later
in the discovery procedure.

To solve this issue set the sas_device's scsi_target pointer to scsi_device's
scsi_target if it is NULL earlier in slave_alloc callback function.

Signed-off-by: default avatarSreekanth Reddy <Sreekanth.Reddy@lsi.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent bc6d4c3b

drivers/scsi/mpt2sas/mpt2sas_scsih.c

+14 −0
Original line number Diff line number Diff line
@@ -1403,6 +1403,7 @@ _scsih_slave_alloc(struct scsi_device *sdev) 
	struct MPT2SAS_DEVICE *sas_device_priv_data;

	struct scsi_target *starget;

	struct _raid_device *raid_device;

	struct _sas_device *sas_device;

	unsigned long flags;



	sas_device_priv_data = kzalloc(sizeof(struct scsi_device), GFP_KERNEL);
@@ -1431,6 +1432,19 @@ _scsih_slave_alloc(struct scsi_device *sdev) 
		spin_unlock_irqrestore(&ioc->raid_device_lock, flags);

	}



	if (!(sas_target_priv_data->flags & MPT_TARGET_FLAGS_VOLUME)) {

		spin_lock_irqsave(&ioc->sas_device_lock, flags);

		sas_device = mpt2sas_scsih_sas_device_find_by_sas_address(ioc,

				sas_target_priv_data->sas_address);

		if (sas_device && (sas_device->starget == NULL)) {

			sdev_printk(KERN_INFO, sdev,

			     "%s : sas_device->starget set to starget @ %d\n",

			     __func__, __LINE__);

			sas_device->starget = starget;

		}

		spin_unlock_irqrestore(&ioc->sas_device_lock, flags);

	}



	return 0;

}