VulnerabilityPublished 6 May 2026Updated 21 Oct 2026

CVE-2026-43115: Linux kernel · srcu: Use irq_work to start GP in tiny SRCU

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in bb37286db65368cb72ba8757ad86299c4e4a73fc : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in bb37286db65368cb72ba8757ad86299c4e4a73fc, a6fc88b22bc8d12ad52e8412c667ec0f5bf055af, 28768bc7ea0b13f558a70f63cc3cfcd32d55d488 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 6 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d8be81735aa89413b333de488251f0e64e2be591, < bb37286db65368cb72ba8757ad86299c4e4a73fc	Fixed in bb37286db65368cb72ba8757ad86299c4e4a73fc
LinuxLinux	Affected ≥ d8be81735aa89413b333de488251f0e64e2be591, < a6fc88b22bc8d12ad52e8412c667ec0f5bf055af	Fixed in a6fc88b22bc8d12ad52e8412c667ec0f5bf055af
LinuxLinux	Affected ≥ d8be81735aa89413b333de488251f0e64e2be591, < 28768bc7ea0b13f558a70f63cc3cfcd32d55d488	Fixed in 28768bc7ea0b13f558a70f63cc3cfcd32d55d488
LinuxLinux	Affected ≥ d8be81735aa89413b333de488251f0e64e2be591, < 2127e6b79d9d579ea538a350d1bbe859e39814d5	Fixed in 2127e6b79d9d579ea538a350d1bbe859e39814d5
LinuxLinux	Affected ≥ d8be81735aa89413b333de488251f0e64e2be591, < 20b98d9ffb09763048a7c84b47403eb0f177272c	Fixed in 20b98d9ffb09763048a7c84b47403eb0f177272c
LinuxLinux	Affected =4.12	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: srcu: Use irq_work to start GP in tiny SRCU Tiny SRCU's srcu_gp_start_if_needed() directly calls schedule_work(), which acquires the workqueue pool->lock. This causes a lockdep splat when call_srcu() is called with a scheduler lock held, due to: call_srcu() [holding pi_lock] srcu_gp_start_if_needed() schedule_work() -> pool->lock workqueue_init() / create_worker() [holding pool->lock] wake_up_process() -> try_to_wake_up() -> pi_lock Also add irq_work_sync() to cleanup_srcu_struct() to prevent a use-after-free if a queued irq_work fires after cleanup begins. Tested with rcutorture SRCU-T and no lockdep warnings. [ Thanks to Boqun for similar fix in patch "rcu: Use an intermediate irq_work to start process_srcu()" ]

References

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