---
id: CVE-2026-80916
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  kcov: fix data corruption and race conditions on PREEMPT_RT

  syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the
  temporary storage used for saving/…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  kcov: fix data corruption and race conditions on PREEMPT_RT

  syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the
  temporary storage used for saving/…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    ef7048d8a614c5f5a9b20513a5428101a744514e
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    8ed3ddf23d39bf5338406bd9f8863d44748cf6ce
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    5dc59fc959b2b5742985d7ef24bccd1868217dc2
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    a2fb8222cde23b0001812ed3acb7c0ea36dd94e2
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    18799e858b407bf355383c9dd6c06477aa437134
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    e11f5b48c82703242a3be7a7ae4b4940b4cb4610
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    22670d1552fe155822b2abf91f920925f7d067b4
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761
  - >-
    Linux >= 5ff3b30ab57da82d8db4f14662a2858cabfbc2c0 <
    2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c
  - Linux 5.8
published: '2026-09-09'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T17:17:46.513'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80916'
references:
  - url: 'https://git.kernel.org/stable/c/18799e858b407bf355383c9dd6c06477aa437134'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/22670d1552fe155822b2abf91f920925f7d067b4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2eed77fdcb0cc48e8eccb2bcd4b7f2c6d650e84c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5dc59fc959b2b5742985d7ef24bccd1868217dc2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8ed3ddf23d39bf5338406bd9f8863d44748cf6ce'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a2fb8222cde23b0001812ed3acb7c0ea36dd94e2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e11f5b48c82703242a3be7a7ae4b4940b4cb4610'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ef7048d8a614c5f5a9b20513a5428101a744514e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f8c9a3ec36b4ee3d4701b9be08f40e7bfbf89761'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-09T17:16:03.094Z'
epss: 0.00182
epssPercentile: 0.07992
---

## Overview

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

kcov: fix data corruption and race conditions on PREEMPT_RT

syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the
temporary storage used for saving/restoring remote KCOV state is currently
allocated as the per-CPU area.

On PREEMPT_RT kernels, softirq handlers run as preemptible task threads
(e.g., ksoftirqd). If a softirq context preempts a task running a remote
KCOV session, it safely saves the task's state into the per-CPU area.
However, if that softirq thread is subsequently preempted by a higher-
priority softirq thread on the same CPU, the second softirq will overwrite
the same per-CPU area, permanently destroying the original task's KCOV
state.

Fix this data corruption by moving the temporary storage from the per-CPU
area to the per-thread area. Since each softirq thread now owns its own
task context, nested softirq preemption no longer causes data overwrites.

Note that while the temporary storage is now on a per-thread basis, the
per-CPU kcov_percpu_data.lock must be retained, for we need to ensure that
kcov_remote_start() and kcov_remote_stop() operate atomically without
racing against asynchronous interrupts that manipulate the current task's
KCOV state.

It is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()
has already called panic() before returning NULL, for there will be no
OOM-killable userspace processes when __init function of built-in module
runs. But this patch also fixes crashing the kernel when vmalloc_node()
in kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL
but kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in

  (1) doing vmalloc() in kcov_remote_start() despite !in_task() context

  (2) out-of-array-bounds access if (1) succeeded but
      kcov->remote_size < CONFIG_KCOV_IRQ_AREA_SIZE

  (3) always leak memory allocated by (1), eventually killing all
      OOM-killable userspace processes

problems.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.