Hang via premature fence-reference release
Published Oct 18, 2026 · Updated Oct 18, 2026
An endless loop in Linux i915 allows local users to hang a kernel ioctl when GEM object destruction races with fence iteration. The i915_gem_busy_ioctl fence iterator repeatedly restarts after object teardown drops fence references before its RCU-protected iteration finishes, although no replacement fence list will arrive. Reachability requires access to the i915 ioctl and concurrent GEM object destruction; the disclosed consequence is an endless loop, with broader system effects unspecified.
Summary
What happened
An endless loop in Linux i915 allows local users to hang a kernel ioctl when GEM object destruction races with fence iteration. The i915_gem_busy_ioctl fence iterator repeatedly restarts after object teardown drops fence references before its RCU-protected iteration finishes, although no replacement fence list will arrive. Reachability requires access to the i915 ioctl and concurrent GEM object destruction; the disclosed consequence is an endless loop, with broader system effects unspecified.
The record
- CVE
- CVE-2026-98521
- Published
- Oct 18, 2026
- Updated
- Oct 18, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- Unavailable
Timeline
How it unfolded
- Oct 18, 2026CVE publishedPublication date reported by the CVE source.
- Oct 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=5.17
- Affected versionversion=912ff2ebd695c582ca4cebf833ad73a378a99f23 <2dd0190e397ec6468095fd3e80e79276a7361449
- Affected versionversion=912ff2ebd695c582ca4cebf833ad73a378a99f23 <4d4ca84213327da1f84ef7af3946dea6b14c5d88
- Affected versionversion=912ff2ebd695c582ca4cebf833ad73a378a99f23 <b12e041aedcf9fa77c6002a49f07eb20d0521b86
- Affected versionversion=912ff2ebd695c582ca4cebf833ad73a378a99f23 <c53db9cc245219af6b528ca022a17ebfa91d80ba
- Affected versionversion=912ff2ebd695c582ca4cebf833ad73a378a99f23 <cc890d3f1b15bf6481dc7270fba0b4fbba572813
- Affected versionversion=912ff2ebd695c582ca4cebf833ad73a378a99f23 <d2da6696e0c4e60414706e607029d0bb0330c67e
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
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