Unknown

CVE-2026-80854 — usb: gadget: f_tcm: keep port count until LUN teardown completes

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: keep port count until LUN teardown completes tcm_usbg_drop_nexus() permits session removal once tpg_port_count reaches zero. However, usbg_port_unlink() currently decrements that count from the fabric_pre_unlink() callback, before core_dev_del_lun() waits for active se_lun references to drain. If removal of the last LUN races a nexus removal, the latter can observe a zero port count and call target_remove_session(). This frees sess_cmd_map while an in-flight struct usbg_cmd, including its work item, can still be accessed. Overlapping the last-LUN unlink with nexus removal reproduces this lifetime violation as a DEBUG_OBJECTS "free active" warning for usbg_cmd_work, followed by a target-core BUG/Oops. The generic target-core unlink path has no callback after core_dev_del_lun() completes. Add an optional fabric_post_unlink() callback and use it for the f_tcm port count. The count now remains nonzero until core_dev_del_lun() has finished draining active LUN references, preventing nexus removal from freeing the session during command completion.

Published Sep 4, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.18%

ahead of 8% of scored CVEs · Oct 26, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ c52661d60f636d17e26ad834457db333bd1df494 and < c494c5562ca69b61a82f566e3b87a445d2c28929≥ c52661d60f636d17e26ad834457db333bd1df494 and < c1f359d9a5efed458946063de65ddbeaacc4f165≥ c52661d60f636d17e26ad834457db333bd1df494 and < 178f59a0bccd3f66cdfa5184310f31a58b7257c4≥ c52661d60f636d17e26ad834457db333bd1df494 and < ad6f0375d2e93a1d8c015463e5e92dfcb26e311b≥ c52661d60f636d17e26ad834457db333bd1df494 and < 2efbfd42441d3ef8137aff2d59e9835e1d5ae780≥ c52661d60f636d17e26ad834457db333bd1df494 and < 85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95≥ c52661d60f636d17e26ad834457db333bd1df494 and < bbd6aa311a9f4dd17822c7557451458d3d2e980b≥ c52661d60f636d17e26ad834457db333bd1df494 and < eaa96a8458f54d6cf0954242ab8b1df2a6fccafa and 2 more ≥ c52661d60f636d17e26ad834457db333bd1df494 and < c39d0916da47d94909391876c9e5bd429ea7b1b9version 3.5	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 26, 2026 · 11 reading(s) · max 0.18%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 4, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

11 on the record

git.kernel.org/stable/c/bbd6aa311a9f4dd17822c7557451458d3d2e980b
NIST National Vulnerability Database
git.kernel.org/stable/c/c494c5562ca69b61a82f566e3b87a445d2c28929
NIST National Vulnerability Database
git.kernel.org/stable/c/eaa96a8458f54d6cf0954242ab8b1df2a6fccafa
NIST National Vulnerability Database
git.kernel.org/stable/c/c1f359d9a5efed458946063de65ddbeaacc4f165
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-80854
GitHub Security Advisories
git.kernel.org/stable/c/178f59a0bccd3f66cdfa5184310f31a58b7257c4
NIST National Vulnerability Database
github.com/advisories/GHSA-g824-q393-34qq
GitHub Security Advisories
git.kernel.org/stable/c/2efbfd42441d3ef8137aff2d59e9835e1d5ae780
NIST National Vulnerability Database
git.kernel.org/stable/c/ad6f0375d2e93a1d8c015463e5e92dfcb26e311b
NIST National Vulnerability Database
git.kernel.org/stable/c/85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95
NIST National Vulnerability Database
git.kernel.org/stable/c/c39d0916da47d94909391876c9e5bd429ea7b1b9
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99092 riscv: patch: fix handling of bpf-jit execmem addresses 1d
Unknown CVE-2026-99093 mm: don't schedule deferred kernel page table freeing while booting 1d
Unknown CVE-2026-99095 drm/vc4: drain the hangcheck timer and works on V3D unbind 1d
Unknown CVE-2026-99096 io_uring/register: don't exempt disabled rings from task restrictions 1d
Unknown CVE-2026-99097 tee: shm: reject zero-sized allocations in tee_dyn_shm_alloc_helper() 1d
Unknown CVE-2026-99098 dm-integrity: fix buffer overflow in inline mode with large tag size 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-80854 is "usb: gadget: f_tcm: keep port count until LUN teardown completes", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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