# CVE-2025-40157: EDAC/i10nm: Skip DIMM enumeration on a disabled memory controller

> A local attacker can cause a kernel crash on Intel Granite Rapids servers by triggering a shift-out-of-bounds error in the EDAC driver during initialization.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Nov 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-40157, DEBIAN-CVE-2025-40157, GHSA-rr63-42vx-4m23, ROOT-OS-DEBIAN-13-CVE-2025-40157, ROOT-OS-UBUNTU-2404-CVE-2025-40157, UBUNTU-CVE-2025-40157

## What is CVE-2025-40157?

CVE-2025-40157 is a denial of service vulnerability in Linux, published on 12 Nov 2025. 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:

EDAC/i10nm: Skip DIMM enumeration on a disabled memory controller

When loading the i10nm_edac driver on some Intel Granite Rapids servers,
a call trace may appear as follows:

  UBSAN: shift-out-of-bounds in drivers/edac/skx_common.c:453:16
  shift exponent -66 is negative
  ...
  __ubsan_handle_shift_out_of_bounds+0x1e3/0x390
  skx_get_dimm_info.cold+0x47/0xd40 [skx_edac_common]
  i10nm_get_dimm_config+0x23e/0x390 [i10nm_edac]
  skx_register_mci+0x159/0x220 [skx_edac_common]
  i10nm_init+0xcb0/0x1ff0 [i10nm_edac]
  ...

This occurs because some BIOS may disable a memory controller if there
aren't any memory DIMMs populated on this memory controller. The DIMMMTR
register of this disabled memory controller contains the invalid value
~0, resulting in the call trace above.

Fix this call trace by skipping DIMM enumeration on a disabled memory
controller.

## Which versions are affected by CVE-2025-40157?


## How do I fix CVE-2025-40157?

Apply the vendor's patch.

## Is CVE-2025-40157 being exploited?

There is no known exploitation of CVE-2025-40157 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40157 and fix it if it is affected.

What it is: CVE-2025-40157 is a denial of service vulnerability in Linux, published on 12 Nov 2025. 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-2025-40157 in the wild and no public exploit code.

Affected product: Linux. 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-2025-40157/ (Markdown: https://insights.sbomify.com/CVE-2025-40157/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40157
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40157
- OSV: https://osv.dev/vulnerability/CVE-2025-40157

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40157/
Summaries are generated and may contain mistakes; the official description above is the record.