6.18-stable review patch. If anyone has any objections, please let me know.
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From: Mike McGowen mike.mcgowen@microchip.com
[ Upstream commit b518e86d1a70a88f6592a7c396cf1b93493d1aab ]
Correct possible race conditions during device removal.
Previously, a scheduled work item to reset a LUN could still execute after the device was removed, leading to use-after-free and other resource access issues.
This race condition occurs because the abort handler may schedule a LUN reset concurrently with device removal via sdev_destroy(), leading to use-after-free and improper access to freed resources.
- Check in the device reset handler if the device is still present in the controller's SCSI device list before running; if not, the reset is skipped.
- Cancel any pending TMF work that has not started in sdev_destroy().
- Ensure device freeing in sdev_destroy() is done while holding the LUN reset mutex to avoid races with ongoing resets.
Fixes: 2d80f4054f7f ("scsi: smartpqi: Update deleting a LUN via sysfs") Reviewed-by: Scott Teel scott.teel@microchip.com Reviewed-by: Scott Benesh scott.benesh@microchip.com Signed-off-by: Mike McGowen mike.mcgowen@microchip.com Signed-off-by: Don Brace don.brace@microchip.com Link: https://patch.msgid.link/20251106163823.786828-3-don.brace@microchip.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/smartpqi/smartpqi_init.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index 03c97e60d36f6..fdc856845a05d 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -6410,10 +6410,22 @@ static int pqi_device_reset(struct pqi_ctrl_info *ctrl_info, struct pqi_scsi_dev
static int pqi_device_reset_handler(struct pqi_ctrl_info *ctrl_info, struct pqi_scsi_dev *device, u8 lun, struct scsi_cmnd *scmd, u8 scsi_opcode) { + unsigned long flags; int rc;
mutex_lock(&ctrl_info->lun_reset_mutex);
+ spin_lock_irqsave(&ctrl_info->scsi_device_list_lock, flags); + if (pqi_find_scsi_dev(ctrl_info, device->bus, device->target, device->lun) == NULL) { + dev_warn(&ctrl_info->pci_dev->dev, + "skipping reset of scsi %d:%d:%d:%u, device has been removed\n", + ctrl_info->scsi_host->host_no, device->bus, device->target, device->lun); + spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags); + mutex_unlock(&ctrl_info->lun_reset_mutex); + return 0; + } + spin_unlock_irqrestore(&ctrl_info->scsi_device_list_lock, flags); + dev_err(&ctrl_info->pci_dev->dev, "resetting scsi %d:%d:%d:%u SCSI cmd at %p due to cmd opcode 0x%02x\n", ctrl_info->scsi_host->host_no, device->bus, device->target, lun, scmd, scsi_opcode); @@ -6594,7 +6606,9 @@ static void pqi_sdev_destroy(struct scsi_device *sdev) { struct pqi_ctrl_info *ctrl_info; struct pqi_scsi_dev *device; + struct pqi_tmf_work *tmf_work; int mutex_acquired; + unsigned int lun; unsigned long flags;
ctrl_info = shost_to_hba(sdev->host); @@ -6621,8 +6635,13 @@ static void pqi_sdev_destroy(struct scsi_device *sdev)
mutex_unlock(&ctrl_info->scan_mutex);
+ for (lun = 0, tmf_work = device->tmf_work; lun < PQI_MAX_LUNS_PER_DEVICE; lun++, tmf_work++) + cancel_work_sync(&tmf_work->work_struct); + + mutex_lock(&ctrl_info->lun_reset_mutex); pqi_dev_info(ctrl_info, "removed", device); pqi_free_device(device); + mutex_unlock(&ctrl_info->lun_reset_mutex); }
static int pqi_getpciinfo_ioctl(struct pqi_ctrl_info *ctrl_info, void __user *arg)