Unknown

CVE-2026-97533 — x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF

In the Linux kernel, the following vulnerability has been resolved: x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF A previous commit protected against races between ptdump and CPA collapse, however one still exists between attribute changes and collapse as reported by Denis V. Lunev (linked). When an attribute change arises, a lockless page table walker obtains a PTE entry, which is later written to via set_pte_atomic(): ... -> change_page_attr_set_clr() -> __change_page_attr_set_clr() -> __change_page_attr() -> _lookup_address_cpa() -> lookup_address_in_pgd_attr() -> [ lockless page table walker ] -> set_pte_atomic() There is nothing preventing a concurrent CPA collapse which can free the PTE that was retrieved here, resulting in a use-after-free. With the mmap write lock taken on init_mm over CPA collapse, resolve this race by acquiring an mmap read lock on init_mm over __change_page_attr_set_clr(). This locks across the whole operation over which the walk and the PTE entry write occurs, solving the race. It is safe to do this here, as no spinlocks are held upon entry to __change_page_attr_set_clr(). However, the lock must not be held over an allocation, as allocation can trigger reclaim and shrinkers may call into CPA recursively, making deadlocks possible (init_mm -> ... -> fs_reclaim -> init_mm). A page table is allocated when a huge page needs to be split: -> change_page_attr_set_clr() -> __change_page_attr_set_clr() -> __change_page_attr() -> split_large_page() [ pagetable_alloc() ] -> __split_large_page() Avoid deadlocks by dropping the mmap lock across pagetable_alloc() in split_large_page() and track whether this is needed by adding a new 'init_mm_read_locked' flag to struct cpa_data. This is safe as __split_large_page() (called with locks re-established) revalidates that the page table entry is the same as it was prior to the locks being dropped and __change_page_attr() repeats the entire page table walk whenever a split occurs, so concurrent split and collapse are accounted for. Concurrent ptdump is also safe as the lock is only dropped over page table allocation during which time the page table has not yet been modified. The CPA_COLLAPSE flag is only set by set_memory_rox(), which exclusively operates upon vmalloc ranges, and on x86 only within the module mapping space. This is important, because some callers directly invoke __change_page_attr_set_clr(), bypassing this lock. However, none of these operate within the module mapping space. * cpa_process_alias() - a recursive helper called by __change_page_attr_set_clr(). * __set_memory_enc_pgtable() - operates on the direct mapping and (via __vmbus_establish_gpadl()) the vmalloc mapping space. * __set_pages_[n]p() - called by set_direct_map_[invalid, default, valid]_noflush(), __kernel_map_pages() - operates on the direct map. * kernel_[un]map_pages_in_pgd() - operates on EFI ranges. This work is based upon Denis V. Lunev's excellent analysis of the bug with gratitude. [ dhansen: move to imperative voice in changelog ]

Published Sep 25, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.21%

ahead of 10% of scored CVEs · Oct 16, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 41d88484c71cd4f659348da41b7b5b3dbd3be1f6 and < e21a9ea81426a85fdb0cdcfcc99d5d9c16b402ab≥ 41d88484c71cd4f659348da41b7b5b3dbd3be1f6 and < cc73b2043d106b467accd38e9b1fc09e0607c056≥ 41d88484c71cd4f659348da41b7b5b3dbd3be1f6 and < d5d8b8662e6e5a565b47a0388640e88402f23274version 6.15	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

3 on the record

git.kernel.org/stable/c/d5d8b8662e6e5a565b47a0388640e88402f23274
NIST National Vulnerability Database
git.kernel.org/stable/c/e21a9ea81426a85fdb0cdcfcc99d5d9c16b402ab
NIST National Vulnerability Database
git.kernel.org/stable/c/cc73b2043d106b467accd38e9b1fc09e0607c056
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 2d
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 2d
Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 3d
Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 3d
Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 3d
Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 3d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-97533 is "x86/mm/pat: Acquire init_mm read lock on attribute changes to avoid UAF", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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