---
id: CVE-2026-74654
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  serial: 8250_dma: Clear stale RX state on shutdown

  serial8250_release_dma() terminates RX DMA and releases the channel, but
  leaves rx_running set
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  serial: 8250_dma: Clear stale RX state on shutdown

  serial8250_release_dma() terminates RX DMA and releases the channel, but
  leaves rx_running set.  If the port is clos…
severity: none
published: '2026-08-22'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74654'
references:
  - url: 'https://git.kernel.org/stable/c/9f2444f4c0e4b06f61bae38da87c9c94c78efa86'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ae05d9e50b6b9f246c110b3bdc03676145c2d0d4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bf4fb620e02962b2b52500a4b3d8420f351eb46a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d06cfb1add4a2d5b393e9e31f49ebbd168beea49'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e10f06ee050a08930e2339b6fec7148fd0b2a8f6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e2fe6a0efecbef00e3ecc2db64dd5afa8c212b41'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e7a5d792cf64a2096e18f1d573cc3d01cba15e92'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e7e3cc6709caa49d1d6ce6c1f7cb305e38675cc9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00177
epssPercentile: 0.06716
ingestedAt: '2026-10-14T13:30:58.528Z'
---

## Overview

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

serial: 8250_dma: Clear stale RX state on shutdown

serial8250_release_dma() terminates RX DMA and releases the channel, but
leaves rx_running set.  If the port is closed while an RX transfer is
active, the stale state remains while rxchan is NULL until the channel is
requested again on the next open.

The DesignWare BUSY workaround added by commit a7b9ce39fbe4
("serial: 8250_dw: Ensure BUSY is deasserted") calls
serial8250_rx_dma_flush() from the LCR write path during startup.  This
happens before serial8250_request_dma() obtains a new RX channel.  On
reopen, the stale rx_running state therefore makes the flush path pass a
NULL channel to dmaengine_pause(), causing a kernel Oops.

Clear rx_running after terminating RX DMA, matching the TX cleanup.  Also
make the flush helper return if the DMA object or RX channel is not
available so startup and teardown paths cannot pass a NULL channel to the
DMAengine API.

## Remediation

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