Vulnerability in Linux kernel (CVE-2026-93781)
Summary
Vulnerability in Linux kernel (CVE-2026-93781). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
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 sched tag until
the error handler thread leaves scsi_restart_operations() and restart
the queues.
For devices with a single driver tag (e.g. USB storage) it is a
guaranteed deadlock and I/O that can never be submitted. This problem
has also been reproduced in our environment.
Locking the door is a best-effort operation, and scsi_eh_lock_door()
already returns silently when the request allocation fails. Pass
BLK_MQ_REQ_NOWAIT to scsi_alloc_request() so the allocation fails
instead of bl…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-93781 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-93781" on the vendor's site.
CVE-2026-93781 (Linux kernel)
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Ubuntu UBUNTU-CVE-2026-93781 linux
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com