---
id: CVE-2026-98832
title: 'blk-cgroup: save IRQ state in blkg_tryget_closest()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  blk-cgroup: save IRQ state in blkg_tryget_closest()

  bio_set_dev() associates the bio with a blkg through bio_associate_blkg().
  If the blkg lookup misses, blkg_tryget_c…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 9327a865e395a53f67dffac4710beb1d4730495e <
    9fcf4317384ce6758c3127a6e8914c54cbb9c8cc
  - >-
    Linux >= 9327a865e395a53f67dffac4710beb1d4730495e <
    327c428ba79b13e4cc5253333a9d5c0aa5579bdf
  - Linux 7.2
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:49:36.925Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98832'
references:
  - url: 'https://git.kernel.org/stable/c/9fcf4317384ce6758c3127a6e8914c54cbb9c8cc'
  - url: 'https://git.kernel.org/stable/c/327c428ba79b13e4cc5253333a9d5c0aa5579bdf'
tags:
  - cve.org
ingestedAt: '2026-10-18T16:47:32.470Z'
---

## Overview

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

blk-cgroup: save IRQ state in blkg_tryget_closest()

bio_set_dev() associates the bio with a blkg through bio_associate_blkg().
If the blkg lookup misses, blkg_tryget_closest() takes q->queue_lock with
spin_lock_irq() and releases it with spin_unlock_irq(), which
unconditionally enables local interrupts.

Callers may call bio_set_dev() with interrupts already disabled, e.g.
dm-thin's pool_map() does so while holding pool->lock taken with
spin_lock_irq().  The nested spin_unlock_irq() then enables interrupts
while pool->lock is still held, so an I/O completion softirq can run on
the same CPU, re-acquire pool->lock (thin_endio(), or overwrite_endio()
-> complete_mapping_preparation()) and deadlock.  lockdep reports this
as inconsistent SOFTIRQ-ON-W to IN-SOFTIRQ-W usage.

Commit 3a762de55b4e ("block: save irq state in blkg_lookup_create()")
fixed the same problem while the lock lived in blkg_lookup_create(), but
commit 9327a865e395 ("blk-cgroup: don't nest queue_lock under rcu in
blkg_lookup_create()") moved the locking into blkg_tryget_closest() and
reverted it to spin_lock_irq().

Save and restore the caller's IRQ state instead.

## Affected

- `Linux >= 9327a865e395a53f67dffac4710beb1d4730495e < 9fcf4317384ce6758c3127a6e8914c54cbb9c8cc`
- `Linux >= 9327a865e395a53f67dffac4710beb1d4730495e < 327c428ba79b13e4cc5253333a9d5c0aa5579bdf`
- `Linux 7.2`

## Remediation

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