Freed-memory access via resctrl worker lifetime race
Published Sep 17, 2026 · Updated Sep 17, 2026
Use-after-free in Linux resctrl allows local users to trigger invalid kernel memory access during CPU hotplug and domain removal. The mbm_handle_overflow() and cqm_handle_limbo() workers wait for cpus_read_lock() while CPU-offline callbacks free their containing rdt_l3_mon_domain, leaving container_of() to access freed memory when execution resumes. The race requires active monitoring work overlapping domain removal; published assessments require high local privileges, while a specific crash or privilege-escalation outcome is not documented.
Summary
What happened
Use-after-free in Linux resctrl allows local users to trigger invalid kernel memory access during CPU hotplug and domain removal. The mbm_handle_overflow() and cqm_handle_limbo() workers wait for cpus_read_lock() while CPU-offline callbacks free their containing rdt_l3_mon_domain, leaving container_of() to access freed memory when execution resumes. The race requires active monitoring work overlapping domain removal; published assessments require high local privileges, while a specific crash or privilege-escalation outcome is not documented.
The record
- CVE
- CVE-2026-93099
- Published
- Sep 17, 2026
- Updated
- Sep 17, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 17, 2026CVE publishedPublication date reported by the CVE source.
- Sep 17, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=24247aeeabe99eab13b798ccccc2dec066dd6f07 <2566b5cd6a275c124e8f154fef6e815f92ec8d5c
- Affected versionversion=24247aeeabe99eab13b798ccccc2dec066dd6f07 <b86dbfe4583bf134932a6cc45bf25b12c10a0b2f
- Affected versionversion=4.14
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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