The code in the drivers/scsi/libsas/sas_scsi_host.c file in the Linux allows a physically proximate attacker to cause a memory leak in ATA command queue and thus a denial of service by triggering certain failure conditions.
An upstream patch:
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1566409]
kernel-4.15.17-200.fc26 has been pushed to the Fedora 26 stable repository. If problems still persist, please make note of it in this bug report.
An analysis shows, this bug is a memory leak via the ATA Error Handler for a device behind a SAS HBA. The Error Handler can be triggered by someone physically unplugging the drive. So the failure can only occur for physically proximate attackers who unplug SAS Host Bus Adapter cables. Red Hat does not consider this bug to be a security flaw, as a physically proximate attacker can cause more harm to a system than just a memory leak.