CVE-2026-43061: In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix TX deadlock when using DMA `dmaengine_terminate_async` does no...

Description

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix TX deadlock when using DMA `dmaengine_terminate_async` does not guarantee that the `__dma_tx_complete` callback will run. The callback is currently the only place where `dma->tx_running` gets cleared. If the transaction is canceled and the callback never runs, then `dma->tx_running` will never get cleared and we will never schedule new TX DMA transactions again. This change makes it so we clear `dma->tx_running` after we terminate the DMA transaction. This is "safe" because `serial8250_tx_dma_flush` is holding the UART port lock. The first thing the callback does is also grab the UART port lock, so access to `dma->tx_running` is serialized.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.09%

0.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-667

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 5.4.291, < 5.5	—
Linux	Linux Kernel	>= 5.10.235, < 5.10.253	—
Linux	Linux Kernel	>= 5.15.179, < 5.15.203	—
Linux	Linux Kernel	>= 6.1.129, < 6.1.167	—
Linux	Linux Kernel	>= 6.6.79, < 6.6.130	—
Linux	Linux Kernel	>= 6.12.16, < 6.12.78	—
Linux	Linux Kernel	>= 6.13.4, < 6.14	—
Linux	Linux Kernel	>= 6.14.1, < 6.18.20	—
Linux	Linux Kernel	>= 6.19, < 6.19.10	—
Linux	Linux Kernel	6.14	—
Linux	Linux Kernel	7.0	Rc1

References

Timeline

Published: May 5, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-43061?

In the Linux kernel, the following vulnerability has been resolved: serial: 8250: Fix TX deadlock when using DMA `dmaengine_terminate_async` does not guarantee that the `__dma_tx_complete` callback will run. The callback is currently the only place where `dma->tx_running` gets cleared. If the transaction is canceled and the callback never runs, then `dma->tx_running` will never get cleared and we will never schedule new TX DMA transactions again. This change makes it so we clear `dma->tx_running` after we terminate the DMA transaction. This is "safe" because `serial8250_tx_dma_flush` is holding the UART port lock. The first thing the callback does is also grab the UART port lock, so access to `dma->tx_running` is serialized.

How severe is CVE-2026-43061?

CVE-2026-43061 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.09% probability of exploitation in the next 30 days.

How do I fix CVE-2026-43061?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.