fs: quota: create dedicated workqueue for quota_release_work

published 2025-11-12 11 mo ago modified 2026-10-19 20 d ago also EUVD-2025-150378

cvss: —; not scored
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits: 0; none known

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

There is a kernel panic due to WARN_ONCE when panic_on_warn is set.

This issue occurs when writeback is triggered due to sync call for an opened file(ie, writeback reason is WB_REASON_SYNC). When f2fs balance is needed at sync path, flush for quota_release_work is triggered. By default quota_release_work is queued to "events_unbound" queue which does not have WQ_MEM_RECLAIM flag. During f2fs balance "writeback" workqueue tries to flush quota_release_work causing kernel panic due to MEM_RECLAIM flag mismatch errors.

This patch creates dedicated workqueue with WQ_MEM_RECLAIM flag for work quota_release_work.

------------[ cut here ]------------ WARNING: CPU: 4 PID: 14867 at kernel/workqueue.c:3721 check_flush_dependency+0x13c/0x148 Call trace: check_flush_dependency+0x13c/0x148 __flush_work+0xd0/0x398 flush_delayed_work+0x44/0x5c dquot_writeback_dquots+0x54/0x318 f2fs_do_quota_sync+0xb8/0x1a8 f2fs_write_checkpoint+0x3cc/0x99c f2fs_gc+0x190/0x750 f2fs_balance_fs+0x110/0x168 f2fs_write_single_data_page+0x474/0x7dc f2fs_write_data_pages+0x7d0/0xd0c do_writepages+0xe0/0x2f4 __writeback_single_inode+0x44/0x4ac writeback_sb_inodes+0x30c/0x538 wb_writeback+0xf4/0x440 wb_workfn+0x128/0x5d4 process_scheduled_works+0x1c4/0x45c worker_thread+0x32c/0x3e8 kthread+0x11c/0x1b0 ret_from_fork+0x10/0x20 Kernel panic - not syncing: kernel: panic_on_warn set ...

Patch / fix

fixed in 1 distros 4 links 5

Linux Linux 5.5, 5.11, 5.16, 6.1.178, 6.6.114, 6.12.54, 6.17.4, 6.18

debian ubuntu suse opensuse

linux Debian 12 6.1.180-1
linux Debian 13 6.12.57-1
linux Debian 14 6.17.6-1

debian advisories DEBIAN-CVE-2025-40196

linux Ubuntu 24.04 LTS 6.8.0-106.106
linux Ubuntu 25.10 6.17.0-14.14
linux-aws Ubuntu 24.04 LTS 6.8.0-1050.53
linux-aws Ubuntu 25.10 6.17.0-1007.7
linux-gcp Ubuntu 24.04 LTS 6.8.0-1052.55
linux-gcp Ubuntu 25.10 6.17.0-1007.7
linux-gke Ubuntu 24.04 LTS 6.8.0-1048.53
linux-ibm Ubuntu 24.04 LTS 6.8.0-1049.49

ubuntu advisories UBUNTU-CVE-2025-40196

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-rt Linux Micro 6.2 6.12.0-160000.8.1
kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.8.1
kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.8.1
kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.8.1
kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.8.1.160000.2.5
kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.8.1
kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.8.1
kernel-kvmsmall SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.8.1

suse advisories SUSE-SU-2026:20012-1 SUSE-SU-2026:20015-1 SUSE-SU-2026:20021-1 SUSE-SU-2026:20562-1

kernel-rt openSUSE Leap 16.0 6.12.0-160000.8.1
dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.8.1
kernel-64kb openSUSE Leap 16.0 6.12.0-160000.8.1
kernel-syms openSUSE Leap 16.0 6.12.0-160000.8.1
kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.8.1
kernel-source openSUSE Leap 16.0 6.12.0-160000.8.1
kernel-default openSUSE Leap 16.0 6.12.0-160000.8.1
kernel-kvmsmall openSUSE Leap 16.0 6.12.0-160000.8.1

opensuse advisories openSUSE-SU-2025:20172-1

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-2025-40196 updated 2026-11-07 cvss 5.5

kernel: fs: quota: create dedicated workqueue for quota_release_work

Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 10 kernel
affected: no fix available “Fix deferred”
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
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-26-295-11 updated 2026-10-22 cvss 0.0

Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.7 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.7 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.7
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

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

Linux Linux
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2025-40196
NVD CVE-2025-40196

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.

Summary