0.0
NA
CVE-2026-98505
mm/damon/vaddr: avoid hw-driven pte updates during damon_hugetlb_mkold()
Description

In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: avoid hw-driven pte updates during damon_hugetlb_mkold() damon_hugetlb_mkold() reads the page table entry into a local variable, unsets the accessed bit in the variable, and updates the page table entry with the updated variable value. If hardware updates the same page table entry in parallel, the hw updates could be lost. For example, hardware-updated dirty bits might be lost. Avoid the parallel updates by clearing the page table entry when reading it together, using huge_ptep_get_and_clear(). If a parallel write to the memory is made after the clearing, the hw will see the page table entry is cleared, trigger page fault and wait until it is handled. The page fault handling will wait for damon_hugetlb_mkold() due to the page table lock. Because hugetlbfs is an in-memory file system and hugetlb pages cannot be reclaimed, no critical issue is expected to my best knowledge. But definitely this is a nasty bug that should be fixed sooner rather than later. The issue was discovered [1] by Sashiko.

INFO

Published Date :

Oct. 18, 2026, 4:17 p.m.

Last Modified :

Oct. 18, 2026, 4:17 p.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products

The following products are affected by CVE-2026-98505 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
Solution
Update the Linux kernel to avoid parallel page table entry updates.
  • Update the Linux kernel to the latest version.
  • Apply the patch for mm/damon/vaddr.
  • Clear page table entries before updating them.
  • Ensure page faults are handled properly.
References to Advisories, Solutions, and Tools
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-98505 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-98505 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-98505 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-98505 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Oct. 18, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: mm/damon/vaddr: avoid hw-driven pte updates during damon_hugetlb_mkold() damon_hugetlb_mkold() reads the page table entry into a local variable, unsets the accessed bit in the variable, and updates the page table entry with the updated variable value. If hardware updates the same page table entry in parallel, the hw updates could be lost. For example, hardware-updated dirty bits might be lost. Avoid the parallel updates by clearing the page table entry when reading it together, using huge_ptep_get_and_clear(). If a parallel write to the memory is made after the clearing, the hw will see the page table entry is cleared, trigger page fault and wait until it is handled. The page fault handling will wait for damon_hugetlb_mkold() due to the page table lock. Because hugetlbfs is an in-memory file system and hugetlb pages cannot be reclaimed, no critical issue is expected to my best knowledge. But definitely this is a nasty bug that should be fixed sooner rather than later. The issue was discovered [1] by Sashiko.
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98505.json">CVE-2026-98505</a>
    Added Reference https://git.kernel.org/stable/c/00457981327c80bcc56e07d4714fe189337a19fa
    Added Reference https://git.kernel.org/stable/c/39c0ceedd54557bdc1542de08d22b2ed33e534e4
    Added Reference https://git.kernel.org/stable/c/6e74ffc9ecf6ec24eee117150da78a1102be74c5
    Added Reference https://git.kernel.org/stable/c/e59cb7eda7c06334a0faf5aa44adb6acf2a1287a
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.