# CVE-2023-54237: net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()

> A missing lock in the Linux kernel SMC module allows a local attacker to trigger a null pointer dereference, causing a system crash.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Dec 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-54237, DEBIAN-CVE-2023-54237, GHSA-c945-9h2g-hv7w, ROOT-OS-DEBIAN-11-CVE-2023-54237, ROOT-OS-UBUNTU-2204-CVE-2023-54237, UBUNTU-CVE-2023-54237

## What is CVE-2023-54237?

CVE-2023-54237 is a critical vulnerability in Linux, published on 30 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

net/smc: fix potential panic dues to unprotected smc_llc_srv_add_link()

There is a certain chance to trigger the following panic:

PID: 5900   TASK: ffff88c1c8af4100  CPU: 1   COMMAND: "kworker/1:48"
 #0 [ffff9456c1cc79a0] machine_kexec at ffffffff870665b7
 #1 [ffff9456c1cc79f0] __crash_kexec at ffffffff871b4c7a
 #2 [ffff9456c1cc7ab0] crash_kexec at ffffffff871b5b60
 #3 [ffff9456c1cc7ac0] oops_end at ffffffff87026ce7
 #4 [ffff9456c1cc7ae0] page_fault_oops at ffffffff87075715
 #5 [ffff9456c1cc7b58] exc_page_fault at ffffffff87ad0654
 #6 [ffff9456c1cc7b80] asm_exc_page_fault at ffffffff87c00b62
    [exception RIP: ib_alloc_mr+19]
    RIP: ffffffffc0c9cce3  RSP: ffff9456c1cc7c38  RFLAGS: 00010202
    RAX: 0000000000000000  RBX: 0000000000000002  RCX: 0000000000000004
    RDX: 0000000000000010  RSI: 0000000000000000  RDI: 0000000000000000
    RBP: ffff88c1ea281d00   R8: 000000020a34ffff   R9: ffff88c1350bbb20
    R10: 0000000000000000  R11: 0000000000000001  R12: 0000000000000000
    R13: 0000000000000010  R14: ffff88c1ab040a50  R15: ffff88c1ea281d00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffff9456c1cc7c60] smc_ib_get_memory_region at ffffffffc0aff6df [smc]
 #8 [ffff9456c1cc7c88] smcr_buf_map_link at ffffffffc0b0278c [smc]
 #9 [ffff9456c1cc7ce0] __smc_buf_create at ffffffffc0b03586 [smc]

The reason here is that when the server tries to create a second link,
smc_llc_srv_add_link() has no protection and may add a new link to
link group. This breaks the security environment protected by
llc_conf_mutex.

## Which versions are affected by CVE-2023-54237?


## How do I fix CVE-2023-54237?

Apply the vendor's patch.

## Is CVE-2023-54237 being exploited?

There is no known exploitation of CVE-2023-54237 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54237 and fix it if it is affected.

What it is: CVE-2023-54237 is a critical vulnerability in Linux, published on 30 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-54237 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-2023-54237/ (Markdown: https://insights.sbomify.com/CVE-2023-54237/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54237
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54237
- OSV: https://osv.dev/vulnerability/CVE-2023-54237

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54237/
Summaries are generated and may contain mistakes; the official description above is the record.