---
id: "CVE-2026-99232"
kind: "vulnerability"
aliases: ["CVE-2026-99232"]
title: "Linux kernel: tracing syscall buffer copy skips user-address check"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "linux"]
not_affected_if: []
published_at: "2026-11-02T16:17:48+00:00"
first_seen_at: "2026-11-02T16:24:06+00:00"
updated_at: "2026-11-02T16:26:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99232", "first_seen_at": "2026-11-02T16:24:06+00:00"}]
---

# Linux kernel: tracing syscall buffer copy skips user-address check

The Linux kernel's syscall tracing code copied syscall buffer arguments with a routine that skips the access check that rejects non-user addresses. The fix switches to the checked copy routine so invalid addresses are rejected and recorded as faulted.

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

## Timeline

- 2026-11-02T16:24:06+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-99232

## From the sources

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

tracing/syscalls: Use copy_from_user for the faultable syscall buffer

syscall_copy_user_array() copies the buffer argument of faultable
syscalls (write, pwrite64, ...) with __copy_from_user(), which skips
access_ok(). Use copy_from_user() instead so a non-user address is
rejected and the entry is recorded as faulted.

It could be a security concern for machines that trust perf a bit too
much.

---

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