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NVD / CVE Program· CNA Linux

CVE-2026-93781: scsi: core: Do not block on tag allocation in scsi_eh_lock_door()

—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.16% (FIRST EPSS).
  • Fixed version: Linux Linux 261c80a6b23e34ba98bcf3f75317e35ecf0a08f0, 3bc7af4cefac1c583f0607f6183a67012436aad9, 6b450c277c106c4e31411067f025d1aaa27c2a02; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1.

Low priority for now. Upgrade to Linux Linux 261c80a6b23e34ba98bcf3f75317e35ecf0a08f0, 3bc7af4cefac1c583f0607f6183a67012436aad9, 6b450c277c106c4e31411067f025d1aaa27c2a02; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 6.6.158.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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 blocking when no tag is available. This breaks the circular dependency and allows the error handler to finish restarting the queues, after which the pending commands are dispatched normally.

Published
Sep 24, 2026
Updated
Oct 3, 2026
EPSS
0.1% · 6th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.16affected
    • 6e68af666f5336254b5715dca591026b7324499a and later · before 3bc7af4cefac1c583f0607f6183a67012436aad9affected · git
    • 6e68af666f5336254b5715dca591026b7324499a and later · before 6b450c277c106c4e31411067f025d1aaa27c2a02affected · git
    • 6e68af666f5336254b5715dca591026b7324499a and later · before 261c80a6b23e34ba98bcf3f75317e35ecf0a08f0affected · git
    • 6e68af666f5336254b5715dca591026b7324499a and later · before dc9e1b6b9080dd6374cc9a38e4b53abca63c3b1baffected · git
    • 6e68af666f5336254b5715dca591026b7324499a and later · before 732cb6bb37fd26863d5786522fb1997e7f5865b4affected · git
    • before 2.6.16not affected · semver
    • 6.1.189 and later · up to and including 6.1.*not affected · semver
    • 6.6.158 and later · up to and including 6.6.*not affected · semver
    • 6.12.111 and later · up to and including 6.12.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-93287Sep 24, 2026 · i2c: smbus: reject oversized block transfers in the common path
    31Monitor
  • ← EarlierCVE-2026-93288Sep 24, 2026 · netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state
    31Monitor
  • Later →CVE-2026-93782Sep 24, 2026 · vhost-scsi: flush backend after device ioctls
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux261c80a6b23e34ba98bcf3f75317e35ecf0a08f0Vendor (CNA)
Linux Linux3bc7af4cefac1c583f0607f6183a67012436aad9Vendor (CNA)
Linux Linux6b450c277c106c4e31411067f025d1aaa27c2a02Vendor (CNA)
Linux Linux732cb6bb37fd26863d5786522fb1997e7f5865b4Vendor (CNA)
Linux Linuxdc9e1b6b9080dd6374cc9a38e4b53abca63c3b1bVendor (CNA)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.06.6.158.1-1 · Release NotesMicrosoft (MSRC)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Not on record for this CVE: patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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