scsi: scsi_debug: Fix possible UAF in sdebug_add_host_helper()

scsi: scsi_debug: Fix possible UAF in sdebug_add_host_helper()

[ Upstream commit e208a1d795a08d1ac0398c79ad9c58106531bcc5 ]

If device_register() fails in sdebug_add_host_helper(), it will goto clean
and sdbg_host will be freed, but sdbg_host->host_list will not be removed
from sdebug_host_list, then list traversal may cause UAF. Fix it.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Yuan Can <yuancan@huawei.com>
Link: https://lore.kernel.org/r/20221117084421.58918-1-yuancan@huawei.com
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>