This is a note to let you know that I've just added the patch titled scsi: mpt3sas: Fix kernel panic during drive powercycle test to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: scsi-mpt3sas-fix-kernel-panic-during-drive-powercycl.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b6c42ad19f12d80326524379b70ef66d414d7c57 Author: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx> Date: Wed Nov 17 16:19:09 2021 +0530 scsi: mpt3sas: Fix kernel panic during drive powercycle test [ Upstream commit 0ee4ba13e09c9d9c1cb6abb59da8295d9952328b ] While looping over shost's sdev list it is possible that one of the drives is getting removed and its sas_target object is freed but its sdev object remains intact. Consequently, a kernel panic can occur while the driver is trying to access the sas_address field of sas_target object without also checking the sas_target object for NULL. Link: https://lore.kernel.org/r/20211117104909.2069-1-sreekanth.reddy@xxxxxxxxxxxx Fixes: f92363d12359 ("[SCSI] mpt3sas: add new driver supporting 12GB SAS") Signed-off-by: Sreekanth Reddy <sreekanth.reddy@xxxxxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c index 49b751a8f5f3b..0e39bb1489ac7 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -2904,7 +2904,7 @@ _scsih_ublock_io_device(struct MPT3SAS_ADAPTER *ioc, u64 sas_address) 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)