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Fencer Vulns
high 7.5

CVE-2026-46304 json

nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free

published 2026-06-08 5 mo ago modified 2026-10-19 20 d ago also EUVD-2026-35169

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 28%
public exploits
0
none known

Summary

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

nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free

nvmet_tcp_release_queue_work() runs on nvmet-wq and can drop the final controller reference through nvmet_cq_put(). If that triggers nvmet_ctrl_free(), the teardown path flushes ctrl->async_event_work on the same nvmet-wq.

Call chain:

nvmet_tcp_schedule_release_queue() kref_put(&queue->kref, nvmet_tcp_release_queue) nvmet_tcp_release_queue() queue_work(nvmet_wq, &queue->release_work) <--- nvmet_wq process_one_work() nvmet_tcp_release_queue_work() nvmet_cq_put(&queue->nvme_cq) nvmet_cq_destroy() nvmet_ctrl_put(cq->ctrl) nvmet_ctrl_free() flush_work(&ctrl->async_event_work) <--- nvmet_wq

Previously Scheduled by :- nvmet_add_async_event queue_work(nvmet_wq, &ctrl->async_event_work);

This trips lockdep with a possible recursive locking warning.

[ 5223.015876] run blktests nvme/003 at 2026-04-07 20:53:55 [ 5223.061801] loop0: detected capacity change from 0 to 2097152 [ 5223.072206] nvmet: adding nsid 1 to subsystem blktests-subsystem-1 [ 5223.088368] nvmet_tcp: enabling port 0 (127.0.0.1:4420) [ 5223.126086] nvmet: Created discovery controller 1 for subsystem nqn.2014-08.org.nvmexpress.discovery for NQN nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349. [ 5223.128453] nvme nvme1: new ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery", addr 127.0.0.1:4420, hostnqn: nqn.2014-08.org.nvmexpress:uuid:0f01fb42-9f7f-4856-b0b3-51e60b8de349 [ 5233.199447] nvme nvme1: Removing ctrl: NQN "nqn.2014-08.org.nvmexpress.discovery"

[ 5233.227718] ============================================ [ 5233.231283] WARNING: possible recursive locking detected [ 5233.234696] 7.0.0-rc3nvme+ #20 Tainted: G O N [ 5233.238434] -------------------------------------------- [ 5233.241852] kworker/u192:6/2413 is trying to acquire lock: [ 5233.245429] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: touch_wq_lockdep_map+0x26/0x90 [ 5233.251438] but task is already holding lock: [ 5233.255254] ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0 [ 5233.261125] other info that might help us debug this: [ 5233.265333] Possible unsafe locking scenario:

[ 5233.269217] CPU0 [ 5233.270795] ---- [ 5233.272436] lock((wq_completion)nvmet-wq); [ 5233.275241] lock((wq_completion)nvmet-wq); [ 5233.278020] *** DEADLOCK ***

[ 5233.281793] May be due to missing lock nesting notation

[ 5233.286195] 3 locks held by kworker/u192:6/2413: [ 5233.289192] #0: ffff888111632548 ((wq_completion)nvmet-wq){+.+.}-{0:0}, at: process_one_work+0x5cc/0x6e0 [ 5233.294569] #1: ffffc9000e2a7e40 ((work_completion)(&queue->release_work)){+.+.}-{0:0}, at: process_one_work+0x1c5/0x6e0 [ 5233.300128] #2: ffffffff82d7dc40 (rcu_read_lock){....}-{1:3}, at: __flush_work+0x62/0x530 [ 5233.304290] stack backtrace: [ 5233.306520] CPU: 4 UID: 0 PID: 2413 Comm: kworker/u192:6 Tainted: G O N 7.0.0-rc3nvme+ #20 PREEMPT(full) [ 5233.306524] Tainted: [O]=OOT_MODULE, [N]=TEST [ 5233.306525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 5233.306527] Workqueue: nvmet-wq nvmet_tcp_release_queue_work [nvmet_tcp] [ 5233.306532] Call Trace: [ 5233.306534] <TASK> [ 5233.306536] dump_stack_lvl+0x73/0xb0 [ 5233.306552] print_deadlock_bug+0x225/0x2f0 [ 5233.306556] __lock_acquire+0x13f0/0x2290 [ 5233.306563] lock_acquire+0xd0/0x300 [ 5233.306565] ? touch_wq_lockdep_map+0x26/0x90 [ 5233.306571] ? __flush_work+0x20b/0x530 [ 5233.306573] ? touch_wq_lockdep_map+0x26/0x90 [ 5233.306577] touch_wq_lockdep_map+0x3b/0x90 [ 5233.306580] ? touch_wq_lockdep_map+0x26/0x90 [ 52 ---truncated---

Patch / fix

  • Linux Linux 4.10, 5.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1
  • linux Debian 12 6.1.176-1
  • linux Debian 13 6.12.88-1
  • linux Debian 14 7.0.7-1

debian advisories DEBIAN-CVE-2026-46304

  • linux Ubuntu 22.04 LTS 5.15.0-186.196
  • linux Ubuntu 24.04 LTS 6.8.0-136.136
  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1112.119
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1061.64
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1112.122
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1064.72

ubuntu advisories UBUNTU-CVE-2026-46304

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.84.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.84.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.84.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.84.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.84.1.150700.17.47.1

suse advisories SUSE-SU-2026:4706-1SUSE-SU-2026:4687-1SUSE-SU-2026:4640-1SUSE-SU-2026:24316-1SUSE-SU-2026:24315-1SUSE-SU-2026:24181-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1openSUSE-SU-2026:11014-1

  • kernel Azure Linux 3.0 6.6.141.1-1

azure linux advisories AZL-89658

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46304 updated cvss 5.5

kernel: nvmet: avoid recursive nvmet-wq flush in nvmet_ctrl_free

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-26-295-16 updated cvss 7.5

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
23 d ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 28% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.