---
id: "CVE-2026-98559"
kind: "vulnerability"
aliases: ["CVE-2026-98559"]
title: "Linux kernel: SMC link-group list race can read freed memory"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["linux-kernel", "rdma", "runtime", "smc"]
not_affected_if: ["smc-module-not-loaded"]
published_at: "2026-10-18T16:17:08+00:00"
first_seen_at: "2026-10-23T21:57:15+00:00"
updated_at: "2026-10-25T05:23:24+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98559", "first_seen_at": "2026-10-23T21:57:15+00:00"}]
---

# Linux kernel: SMC link-group list race can read freed memory

The Linux kernel's SMC (Shared Memory Communications) code traversed a link-group list without holding its lock, so a concurrent termination could free an entry while it was still being read. An attacker could potentially trigger a use-after-free, the sources do not say what they can get beyond a crash or memory corruption.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- unknown

## Fix

- Update to a Linux kernel release that contains the upstream commit fixing net/smc smcr_port_err() locking; the sources do not name the fixed version.

## Timeline

- 2026-10-23T21:57:15+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98559

## From the sources

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

net/smc: fix UAF on lgr list traversal in smcr_port_err()

smcr_port_err() traverses smc_lgr_list.list without holding
smc_lgr_list.lock, allowing a concurrent smc_lgr_terminate_sched()
to free an lgr while it is still being dereferenced.

Hold smc_lgr_list.lock across the traversal. Update
smc_ib_gid_check() to call smcr_port_err() after releasing the lock.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_