scsi: scsi_transport_sas: Check kzalloc() return value

Check whether memory allocation succeeded before dereferencing
the pointer to the allocated memory.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_transport_sas.c

@@ -421,6 +421,9 @@ sas_tlr_supported(struct scsi_device *sdev)
 	char *buffer = kzalloc(vpd_len, GFP_KERNEL);
 	int ret = 0;
 
+	if (!buffer)
+		goto out;
+
 	if (scsi_get_vpd_page(sdev, 0x90, buffer, vpd_len))
 		goto out;