CVE-2026-93781

/// Technical description

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

scsi: core: Do not block on tag allocation in scsi_eh_lock_door()

scsi_eh_lock_door() is called from scsi_restart_operations() while the

host is still in the SHOST_RECOVERY state, i.e. before the host is

switched back to SHOST_RUNNING and scsi_run_host_queues() restarts the

queues. It allocates a request via scsi_alloc_request() with no flags,

so blk_mq_get_tag() may block waiting for a free sched tag when all tags

are already in use.

Those tags can be held by commands that were just requeued by

scsi_eh_flush_done_q() during error handling. Such commands cannot be

dispatched until the host leaves SHOST_RECOVERY and

scsi_run_host_queues() is called - which only happens *after*

scsi_eh_lock_door() returns.

This forms a circular dependency:

- scsi_eh_lock_door(), running in the SCSI error handler thread, waits

for a sched tag held by a requeued command;

- the requeued command cannot complete and release its

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References