---
id: CVE-2026-98344
title: "In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: Fix device kref underflow in dma_chan_put()\n\ndma_chan_get() takes chan->device->ref only on the slow path:\n\n\t/* no kref on fast path */\n\tif (chan->client_cou…"
summary: "In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: Fix device kref underflow in dma_chan_put()\n\ndma_chan_get() takes chan->device->ref only on the slow path:\n\n\t/* no kref on fast path */\n\tif (chan->client_cou…"
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    036b527f92570206da4b8c40b38f8d689e29d0f3
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    57f7f1c6827be7d8f80feca48d2125fb91c6f6ed
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    7c3f4ce651d43705f9ec7f778f642a90d5ff4fba
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    de2677e57d3161390d8a508f08cddec6ef7e4b23
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    1a0d9b406febf23054ad595fd47b29325e70fb2d
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    77906ac448d2fa81fa710ae26c0e591ebdc81154
  - >-
    Linux >= 8ad342a863590b24ce77681b7e081363fb3333f7 <
    44dab659064eb5c10adb0306510eebe848ed592d
  - Linux 5.6
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T09:18:27.323'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98344'
references:
  - url: 'https://git.kernel.org/stable/c/036b527f92570206da4b8c40b38f8d689e29d0f3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1a0d9b406febf23054ad595fd47b29325e70fb2d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/44dab659064eb5c10adb0306510eebe848ed592d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/57f7f1c6827be7d8f80feca48d2125fb91c6f6ed'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5fb1797a8c9485e40e5492fa0338ab5c7d1f3fef'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/77906ac448d2fa81fa710ae26c0e591ebdc81154'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7c3f4ce651d43705f9ec7f778f642a90d5ff4fba'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/de2677e57d3161390d8a508f08cddec6ef7e4b23'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-06T08:50:17.400Z'
---

## Overview

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

dmaengine: Fix device kref underflow in dma_chan_put()

dma_chan_get() takes chan->device->ref only on the slow path:

	/* no kref on fast path */
	if (chan->client_count) {
		__module_get(owner);
		chan->client_count++;
		return 0;
	}
	if (!try_module_get(owner))
		return -ENODEV;
	if (!dma_device_get(chan->device)) { // calls kref_get_unless_zero()

dma_chan_put() drops the ref unconditionally, so every fast-path
get/put pair drops one extra device reference.

The bug fires when two conditions hold together: a non-private
provider has a persistent client holding chan->client_count > 0
and another client cycles dmaengine_get()/dmaengine_put().
When the kref hits zero, the subsequent dma_find_channel() returns
NULL even though the provider module is still loaded.

Fix this by dropping device->ref only on the last put, matching the
single slow-path get.

## Remediation

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