This is a note to let you know that I've just added the patch titled
scsi: mpt3sas: fix oops in error handlers after shutdown/unload
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: scsi-mpt3sas-fix-oops-in-error-handlers-after-shutdown-unload.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 9ff549ffb4fb4cc9a4b24d1de9dc3e68287797c4 Mon Sep 17 00:00:00 2001
From: Mauricio Faria de Oliveira mauricfo@linux.vnet.ibm.com Date: Fri, 16 Feb 2018 20:39:57 -0200 Subject: scsi: mpt3sas: fix oops in error handlers after shutdown/unload
From: Mauricio Faria de Oliveira mauricfo@linux.vnet.ibm.com
commit 9ff549ffb4fb4cc9a4b24d1de9dc3e68287797c4 upstream.
This patch adds checks for 'ioc->remove_host' in the SCSI error handlers, so not to access pointers/resources potentially freed in the PCI shutdown/module unload path. The error handlers may be invoked after shutdown/unload, depending on other components.
This problem was observed with kexec on a system with a mpt3sas based adapter and an infiniband adapter which takes long enough to shutdown:
The mpt3sas driver finished shutting down / disabled interrupt handling, thus some commands have not finished and timed out.
Since the system was still running (waiting for the infiniband adapter to shutdown), the scsi error handler for task abort of mpt3sas was invoked, and hit an oops -- either in scsih_abort() because 'ioc->scsi_lookup' was NULL without commit dbec4c9040ed ("scsi: mpt3sas: lockless command submission"), or later up in scsih_host_reset() (with or without that commit), because it eventually called mpt3sas_base_get_iocstate().
After the above commit, the oops in scsih_abort() does not occur anymore (_scsih_scsi_lookup_find_by_scmd() is no longer called), but that commit is too big and out of the scope of linux-stable, where this patch might help, so still go for the changes.
Also, this might help to prevent similar errors in the future, in case code changes and possibly tries to access freed stuff.
Note the fix in scsih_host_reset() is still important anyway.
Signed-off-by: Mauricio Faria de Oliveira mauricfo@linux.vnet.ibm.com Acked-by: Sreekanth Reddy Sreekanth.Reddy@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -2998,7 +2998,8 @@ scsih_abort(struct scsi_cmnd *scmd) _scsih_tm_display_info(ioc, scmd);
sas_device_priv_data = scmd->device->hostdata; - if (!sas_device_priv_data || !sas_device_priv_data->sas_target) { + if (!sas_device_priv_data || !sas_device_priv_data->sas_target || + ioc->remove_host) { sdev_printk(KERN_INFO, scmd->device, "device been deleted! scmd(%p)\n", scmd); scmd->result = DID_NO_CONNECT << 16; @@ -3060,7 +3061,8 @@ scsih_dev_reset(struct scsi_cmnd *scmd) _scsih_tm_display_info(ioc, scmd);
sas_device_priv_data = scmd->device->hostdata; - if (!sas_device_priv_data || !sas_device_priv_data->sas_target) { + if (!sas_device_priv_data || !sas_device_priv_data->sas_target || + ioc->remove_host) { sdev_printk(KERN_INFO, scmd->device, "device been deleted! scmd(%p)\n", scmd); scmd->result = DID_NO_CONNECT << 16; @@ -3122,7 +3124,8 @@ scsih_target_reset(struct scsi_cmnd *scm _scsih_tm_display_info(ioc, scmd);
sas_device_priv_data = scmd->device->hostdata; - if (!sas_device_priv_data || !sas_device_priv_data->sas_target) { + if (!sas_device_priv_data || !sas_device_priv_data->sas_target || + ioc->remove_host) { starget_printk(KERN_INFO, starget, "target been deleted! scmd(%p)\n", scmd); scmd->result = DID_NO_CONNECT << 16; @@ -3179,7 +3182,7 @@ scsih_host_reset(struct scsi_cmnd *scmd) ioc->name, scmd); scsi_print_command(scmd);
- if (ioc->is_driver_loading) { + if (ioc->is_driver_loading || ioc->remove_host) { pr_info(MPT3SAS_FMT "Blocking the host reset\n", ioc->name); r = FAILED;
Patches currently in stable-queue which might be from mauricfo@linux.vnet.ibm.com are
queue-4.15/scsi-mpt3sas-wait-for-and-flush-running-commands-on-shutdown-unload.patch queue-4.15/scsi-mpt3sas-fix-oops-in-error-handlers-after-shutdown-unload.patch