PatchSiren cyber security CVE debrief
CVE-2026-72174 Linux CVE debrief
A deadlock vulnerability exists in the Linux kernel when handling PAGEMAP_SCAN ioctl requests on hugetlb VMAs. The issue arises when the scan encounters an unpopulated part of the range, causing the thread to hang unkillably. This is due to a self-deadlock in pagemap_scan_pte_hole(), where the hugetlb vma lock is held for read and then attempted to be taken for write, leading to a block in down_write().
- Vendor
- Linux
- Product
- Unknown
- CVSS
- Unknown
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-08-15
- Original CVE updated
- 2026-08-15
- Advisory published
- 2026-08-15
- Advisory updated
- 2026-08-15
Who should care
Linux kernel developers and maintainers, system administrators, and users of Linux-based systems, especially those responsible for managing and securing Linux environments, should be aware of this vulnerability and take necessary actions to mitigate its impact. This includes reviewing and updating Linux kernel configurations to ensure hugetlb VMAs are properly handled and monitoring system logs for potential denial-of-service attempts. Additionally, Linux distribution maintainers and security teams should prioritize applying the kernel patch to fix the hugetlb self-deadlock vulnerability. Users of Linux-based systems should also be aware of the potential risks and take steps to protect their systems, such as keeping their kernels up-to-date and applying security patches promptly. Furthermore, security teams and vulnerability management professionals should assess the potential impact of this vulnerability on their organization's Linux-based systems and take proactive measures to mitigate its effects. This may involve conducting vulnerability scans, reviewing system configurations, and implementing compensating controls to reduce the risk of exploitation. By taking these steps, Linux kernel developers, maintainers, and users can help prevent potential attacks and ensure the security and stability of their systems. The vulnerability's impact can be mitigated by applying the kernel patch, reviewing and updating Linux kernel configurations, and monitoring system logs for potential denial-of-service attempts. Linux kernel developers and maintainers should prioritize fixing the hugetlb self-deadlock vulnerability to prevent potential attacks. System administrators and users of Linux-based systems should also take necessary precautions to protect their systems from potential exploitation. This includes keeping their kernels up-to-date, applying security patches promptly, and monitoring system logs for potential security incidents. By working together, Linux kernel developers, maintainers, and users can help prevent potential attacks and ensure the security and stability of Linux-based systems. Linux kernel developers and maintainers should also consider providing more
Technical summary
The Linux kernel vulnerability causes a self-deadlock in pagemap_scan_pte_hole() when handling PAGEMAP_SCAN ioctl requests on hugetlb VMAs. The issue arises when the scan encounters an unpopulated part of the range, causing the thread to hang unkillably. The vulnerability is resolved by faulting in the page table and installing the uffd-wp marker directly with make_uffd_wp_huge_pte() under the page-table lock.
Defensive priority
High
Recommended defensive actions
- Apply the kernel patch to fix the hugetlb self-deadlock vulnerability
- Review and update Linux kernel configurations to ensure hugetlb VMAs are properly handled
- Monitor system logs for potential denial-of-service attempts
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
- Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
- Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
Evidence notes
The vulnerability is caused by a self-deadlock in pagemap_scan_pte_hole() when handling PAGEMAP_SCAN ioctl requests on hugetlb VMAs. The issue is resolved by faulting in the page table and installing the uffd-wp marker directly with make_uffd_wp_huge_pte() under the page-table lock, rather than routing through uffd_wp_range().
Sources and references
Verified primary and authoritative sources
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CVE-2026-72174 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-72174
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-72174 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-72174
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/18b8a9700610299819d21fd0ea85d24726d17f65
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/43b987ed35be9be21a303d1036d4241fec9943df
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/a6ac03652d9edc30c2912037ac83beb42cc67f8e
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/e92d92bbafb264dc0518d52b846a3c07ed8d523f
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.