Home/CVE/In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix circular locking dependency in nci_cl
CVE

CVE-2026-31509

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix circular locking dependency in nci_cl

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix circular locking dependency in nci_close_device nci_close_device() flushes rx_wq and tx_wq while holding req_lock. This causes a circular locking dependency because nci_rx_work() running on rx_wq can end up taking req_lock too: nci_rx_work - nci_rx_data_packet - nci_data_exchange_complete - __sk_destruct - rawsock_destruct - nfc_deactivate_target - nci_deactivate_target - nci_request - mutex_lock(&ndev-req_lock) Move the flush of rx_wq after req_lock has been released. This should safe (I think) because NCI_UP has already been cleared and the transport is closed, so the work will see it and return -ENETDOWN.

NIPA has been hitting this running the nci selftest with a debug kernel on roughly 4% of the runs.

MEDIUM · CVSS 5.5 EPSS 0.00014
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
Look this up elsewhere - one-click external pivots
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▸ How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2026-31509, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).
◆

ATT&CK techniques

1

Techniques this CVE enables - linked via CWECAPECATT&CK. High◆ = named directly in ATT&CK or Nuclei templates.

T1499.004 · Application or System Exploitation
▤ Build a SIEM detection for these techniques
▤

CAPEC attack patterns

3

Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.

CAPEC-CAPEC-25 · Forced Deadlock CAPEC-CAPEC-26 · Leveraging Race Conditions CAPEC-CAPEC-27 · Leveraging Race Conditions via Symbolic Links
⬡

Weakness Classification

CWE-667Improper Locking
▤

Affected Products & Versions

8
linux kernel>= 3.2.1 and < 5.10.253
linux kernel>= 5.11 and < 5.15.203
linux kernel>= 5.16 and < 6.1.168
linux kernel>= 6.2 and < 6.6.131
linux kernel>= 6.7 and < 6.12.80
linux kernel>= 6.13 and < 6.18.21
linux kernel>= 6.19 and < 6.19.11
linux kernelall versions
📦

Fixed versions by distribution

17
The package version that resolves this CVE on each Linux distribution, from the vendor’s published security data. fixed in shows a patched version exists; open means the package is listed as affected with no fix yet.
suse sle15cluster-md-kmp-default open
suse sle15dlm-kmp-default open
suse sle15gfs2-kmp-default open
suse sle15kernel-default open
suse sle15kernel-default-base open
suse sle15kernel-default-devel open
suse sle15kernel-default-extra open
suse sle15kernel-default-livepatch open
suse sle15kernel-default-livepatch-devel open
suse sle15kernel-default-man open
suse sle15kernel-devel open
suse sle15kernel-devel-rt open
suse sle15kernel-macros open
suse sle15kernel-source open
suse sle15kernel-source-rt open
suse sle15ocfs2-kmp-default open
suse sle15reiserfs-kmp-default open
▣

Scoring & Timeline

5.5
MEDIUM · CVSS v3.1 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD22 Apr 2026 · 02:16 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
⚑

Vendor Advisories

1
msrcCVE-2026-31509
🔗

References & Sources

8
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://git.kernel.org/stable/c/09143c0e8f3b03517e6233aad42f45c794d8df8ePatch
https://git.kernel.org/stable/c/1edc12d2bbcb7a8d0f1088e6fccb9d8c01bb1289Patch
https://git.kernel.org/stable/c/4527025d440ce84bf56e75ce1df2e84cb8178616Patch
https://git.kernel.org/stable/c/5eef9ebec7f5738f12cadede3545c05b34bf5ac3Patch
https://git.kernel.org/stable/c/7ed00a3edc8597fe2333f524401e2889aa1b5edfPatch
https://git.kernel.org/stable/c/ca54e904a071aa65ef3ad46ba42d51aaac6b73b4Patch
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