In the Linux kernel, the following vulnerability has been resolved: scsi: core: Run queues for...

In the Linux kernel, the following vulnerability has been resolved:

scsi: core: Run queues for all non-SDEV_DEL devices from scsi_run_host_queues

While a SCSI host is in a recovery state, scsi_mq_requeue_cmd() will not set the requeue list for a requeued command to be kicked in the future. The expectation is a call to scsi_run_host_queues() will kick all SCSI devices once the recovery state is cleared.

However, scsi_run_host_queues() uses shost_for_each_device() which uses scsi_device_get() and so will ignore devices in a partially removed state like SDEV_CANCEL. But these devices may also have requeued requests, leaving their requests stuck from not being kicked and causing the removal process of the device to hang.

scsi_run_host_queues() needs to run against more devices than the macro shost_for_each_device() allows. Instead of using the too limiting scsi_device_get() state checks, only ignore devices in SDEV_DEL state or when unable to acquire a reference. Attempt to run the queues for all other devices when scsi_run_host_queues() is called.