# CVE-2026-23097: migrate: correct lock ordering for hugetlb file folios

> A lock ordering error in the Linux kernel's hugetlb migration path can cause a deadlock, leading to a denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Feb 2026
- **Updated:** 19 Oct 2026
- **Also known as:** ALSA-2026:3463, ALSA-2026:3464, AZL-77181, BELL-CVE-2026-23097, DEBIAN-CVE-2026-23097, GHSA-3gqm-m375-7mp2, RHSA-2026:3463, RHSA-2026:3464, RLSA-2026:3463, RLSA-2026:3464, ROOT-OS-DEBIAN-11-CVE-2026-23097, ROOT-OS-DEBIAN-12-CVE-2026-23097, ROOT-OS-DEBIAN-13-CVE-2026-23097, ROOT-OS-UBUNTU-2204-CVE-2026-23097, ROOT-OS-UBUNTU-2404-CVE-2026-23097, UBUNTU-CVE-2026-23097

## What is CVE-2026-23097?

CVE-2026-23097 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

migrate: correct lock ordering for hugetlb file folios

Syzbot has found a deadlock (analyzed by Lance Yang):

1) Task (5749): Holds folio_lock, then tries to acquire i_mmap_rwsem(read lock).
2) Task (5754): Holds i_mmap_rwsem(write lock), then tries to acquire
folio_lock.

migrate_pages()
  -> migrate_hugetlbs()
    -> unmap_and_move_huge_page()     <- Takes folio_lock!
      -> remove_migration_ptes()
        -> __rmap_walk_file()
          -> i_mmap_lock_read()       <- Waits for i_mmap_rwsem(read lock)!

hugetlbfs_fallocate()
  -> hugetlbfs_punch_hole()           <- Takes i_mmap_rwsem(write lock)!
    -> hugetlbfs_zero_partial_page()
     -> filemap_lock_hugetlb_folio()
      -> filemap_lock_folio()
        -> __filemap_get_folio        <- Waits for folio_lock!

The migration path is the one taking locks in the wrong order according to
the documentation at the top of mm/rmap.c.  So expand the scope of the
existing i_mmap_lock to cover the calls to remove_migration_ptes() too.

This is (mostly) how it used to be after commit c0d0381ade79.  That was
removed by 336bf30eb765 for both file & anon hugetlb pages when it should
only have been removed for anon hugetlb pages.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2026-23097?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `bpftool` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-abi-stablelists` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-core` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-cross-headers` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-debug` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-debug-core` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-debug-devel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-debug-modules` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-debug-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-devel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-doc` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-headers` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-modules` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-rt` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-core` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-debug` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-debug-core` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-debug-devel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-debug-modules` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-debug-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-devel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-modules` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-rt-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.rt7.450.el8_10 |
| `kernel-tools` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-tools-libs` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-tools-libs-devel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-zfcpdump` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-zfcpdump-core` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-zfcpdump-devel` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-zfcpdump-modules` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `kernel-zfcpdump-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `perf` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `python3-perf` | AlmaLinux:8 | All versions | 4.18.0-553.109.1.el8_10 |
| `bpftool` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.109.1.el8_10 |
| `bpftool-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.109.1.el8_10 |
| `kernel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.109.1.el8_10 |
| `kernel-abi-stablelists` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.109.1.el8_10 |
| `kernel-core` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.109.1.el8_10 |

Products: Linux kernel.

## How do I fix CVE-2026-23097?

Apply the vendor's patch.

## Is CVE-2026-23097 being exploited?

There is no known exploitation of CVE-2026-23097 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23097 and fix it if it is affected.

What it is: CVE-2026-23097 is a medium-severity vulnerability in Linux kernel, published on 4 Feb 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-23097 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-23097/ (Markdown: https://insights.sbomify.com/CVE-2026-23097/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23097
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23097
- OSV: https://osv.dev/vulnerability/CVE-2026-23097

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23097/
Summaries are generated and may contain mistakes; the official description above is the record.