VulnerabilityPublished 18 Oct 2026

CVE-2026-98832: Linux kernel · blk-cgroup: save IRQ state in blkg_tryget_closest()

Source GCVE Database

Authoritative record:CVE-2026-98832· Medium

Not known to be exploited : upgrade to 327c428ba79b13e4cc5253333a9d5c0aa5579bdf or 9fcf4317384ce6758c3127a6e8914c54cbb9c8cc when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

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 327c428ba79b13e4cc5253333a9d5c0aa5579bdf, 9fcf4317384ce6758c3127a6e8914c54cbb9c8cc

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 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.

ghsa-9gxg-wj69-fwm2

What to do

Upgrade Linux kernel to 327c428ba79b13e4cc5253333a9d5c0aa5579bdf or 9fcf4317384ce6758c3127a6e8914c54cbb9c8cc.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 9327a865e395a53f67dffac4710beb1d4730495e, < 327c428ba79b13e4cc5253333a9d5c0aa5579bdf	Fixed in 327c428ba79b13e4cc5253333a9d5c0aa5579bdf
LinuxLinux	Affected ≥ 9327a865e395a53f67dffac4710beb1d4730495e, < 9fcf4317384ce6758c3127a6e8914c54cbb9c8cc	Fixed in 9fcf4317384ce6758c3127a6e8914c54cbb9c8cc
LinuxLinux	Affected =7.2	Fixed in–

AI-suggested

The fix involves saving and restoring the caller's IRQ state in blkg_tryget_closest() to prevent enabling interrupts while holding locks.

Description

A vulnerability in the Linux kernel's blk-cgroup subsystem involves improper handling of interrupt states in the function blkg_tryget_closest(). This can lead to deadlocks due to interrupts being enabled while a spinlock is held, allowing nested lock acquisition in softirq context. The issue arises when bio_set_dev() is called with interrupts disabled, but blkg_tryget_closest() unconditionally enables interrupts, causing inconsistent lock usage and potential deadlock. The problem was introduced after changes to locking mechanisms and requires saving and restoring the caller's IRQ state to prevent this condition.

Impact

This vulnerability can cause deadlocks in the Linux kernel blk-cgroup subsystem when interrupts are enabled while holding a spinlock, leading to inconsistent lock usage and potential system hangs or degraded performance. It affects kernel stability and reliability but does not directly indicate privilege escalation or data corruption.

Summary

The Linux kernel blk-cgroup vulnerability (CVE-2026-98832) stems from improper interrupt state management in blkg_tryget_closest(). Specifically, bio_set_dev() associates a bio with a block group (blkg), and if the blkg lookup misses, blkg_tryget_closest() acquires the queue lock using spin_lock_irq() and releases it with spin_unlock_irq(), which unconditionally enables local interrupts. If the caller had interrupts disabled (e.g., dm-thin's pool_map()), this leads to interrupts being enabled while holding a spinlock, allowing an I/O completion softirq to run on the same CPU and re-acquire the same lock, causing a deadlock. Previous fixes were reverted due to changes in locking location. The correct fix involves saving and restoring the caller's IRQ state to avoid enabling interrupts unexpectedly.

References

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