---
id: "CVE-2026-98862"
kind: "vulnerability"
aliases: ["CVE-2026-98862"]
title: "Linux kernel audit: use-after-free in audit rule cleanup on directory removal"
severity: "unknown"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["auditd", "kernel", "linux", "other"]
not_affected_if: ["no-audit-rules", "no-exe-filter"]
published_at: "2026-10-18T16:17:40+00:00"
first_seen_at: "2026-10-23T21:57:17+00:00"
updated_at: "2026-10-25T05:12:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98862", "first_seen_at": "2026-10-23T21:57:17+00:00"}]
---

# Linux kernel audit: use-after-free in audit rule cleanup on directory removal

When a watched audit directory is removed, the kernel can free an executable mark while another task is still evaluating the audit rule, causing a use-after-free. The sources do not say what an attacker gets beyond the memory corruption itself.

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

## How to check

- `uname -r` and compare against the fixed kernel version, which the sources do not name
- Check whether auditd rules use `-F exe=` combined with directory watches (`auditctl -l`)

## Fix

- Update to a Linux kernel release that includes the upstream commit 'audit: fix exe mark UAF in kill_rules()'; the fixed version is unknown from these sources

## Timeline

- 2026-10-23T21:57:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98862

## From the sources

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

audit: fix exe mark UAF in kill_rules()

kill_rules() removes mixed AUDIT_DIR and AUDIT_EXE rules when an audit
tree is pruned. It drops entry->rule.exe before removing the rule from
the RCU-visible filter lists.

After a rule has been installed with AUDIT_ADD_RULE, which requires
CAP_AUDIT_CONTROL, removing the watched directory can race with another
task that is still evaluating the rule. In that case, fsnotify can free
the executable mark before the reader reaches audit_mark_compare(),
causing a use-after-free.

KASAN reports:

    BUG: KASAN: slab-use-after-free in audit_mark_compare+0x8d/0xa0

Unlink the published rules from the RCU-visible lists and retain them
on tree->rules for cleanup. If any rule has an executable mark, wait for
a single RCU grace period before removing the marks and scheduling the
entries for freeing. Otherwise, call_rcu() already provides the required
deferred freeing without a synchronous wait.

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