VulnerabilityPublished 18 Oct 2026

CVE-2026-98521: Linux kernel · drm/i915: fix incorrect RCU teardown order

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in d2da6696e0c4e60414706e607029d0bb0330c67e : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in d2da6696e0c4e60414706e607029d0bb0330c67e, cc890d3f1b15bf6481dc7270fba0b4fbba572813, c53db9cc245219af6b528ca022a17ebfa91d80ba +3

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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 912ff2ebd695c582ca4cebf833ad73a378a99f23, < d2da6696e0c4e60414706e607029d0bb0330c67e	Fixed in d2da6696e0c4e60414706e607029d0bb0330c67e
LinuxLinux	Affected ≥ 912ff2ebd695c582ca4cebf833ad73a378a99f23, < cc890d3f1b15bf6481dc7270fba0b4fbba572813	Fixed in cc890d3f1b15bf6481dc7270fba0b4fbba572813
LinuxLinux	Affected ≥ 912ff2ebd695c582ca4cebf833ad73a378a99f23, < c53db9cc245219af6b528ca022a17ebfa91d80ba	Fixed in c53db9cc245219af6b528ca022a17ebfa91d80ba
LinuxLinux	Affected ≥ 912ff2ebd695c582ca4cebf833ad73a378a99f23, < b12e041aedcf9fa77c6002a49f07eb20d0521b86	Fixed in b12e041aedcf9fa77c6002a49f07eb20d0521b86
LinuxLinux	Affected ≥ 912ff2ebd695c582ca4cebf833ad73a378a99f23, < 4d4ca84213327da1f84ef7af3946dea6b14c5d88	Fixed in 4d4ca84213327da1f84ef7af3946dea6b14c5d88
LinuxLinux	Affected ≥ 912ff2ebd695c582ca4cebf833ad73a378a99f23, < 2dd0190e397ec6468095fd3e80e79276a7361449	Fixed in 2dd0190e397ec6468095fd3e80e79276a7361449

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in Linux kernel commits identified by hashes d2da6696e0c4e60414706e607029d0bb0330c67e, cc890d3f1b15bf6481dc7270fba0b4fbba572813, c53db9cc245219af6b528ca022a17ebfa91d80ba, b12e041aedcf9fa77c6002a49f07eb20d0521b86, 4d4ca84213327da1f84ef7af3946dea6b14c5d88, and 2dd0190e397ec6468095fd3e80e79276a7361449. Users and administrators should update to a Linux kernel version including these fixes to remediate the issue.

Description

CVE-2026-98521 is a vulnerability in the Linux kernel's drm/i915 driver where an incorrect Read-Copy-Update (RCU) teardown order can cause an endless loop during fence iteration. This occurs when a GEM object is destroyed concurrently while i915_gem_busy_ioctl is running, leading to improper handling of dma_fence references and an infinite loop in dma_resv_for_each_fence_unlocked(). The issue is fixed by deferring fence reference drops until after the RCU grace period.

Impact

The vulnerability can cause an endless loop in the kernel code path handling GEM object fences, potentially leading to a denial of service by hanging the affected process or kernel thread. Memory is not freed prematurely, but the infinite loop can degrade system stability or responsiveness.

Summary

The vulnerability in Linux kernel drm/i915 involves i915_gem_busy_ioctl using dma_resv_for_each_fence_unlocked() to iterate over fences without holding a reference but only the RCU read lock. Concurrent destruction of the GEM object causes dma_fence references to be dropped prematurely. dma_resv_for_each_fence_unlocked() then encounters a destroyed dma_fence and restarts the loop indefinitely because no new fence list is installed, resulting in an endless loop. The fix delays dropping fence references until after the RCU grace period to prevent this condition.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 10:53 UTC

Technical details

References

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