CVE-2026-43061: serial: 8250: Fix TX deadlock when using DMA
In the Linux kernel, the following vulnerability has been resolved:
serial: 8250: Fix TX deadlock when using DMA
dmaengineterminateasync does not guarantee that the dmatxcomplete callback will run. The callback is currently the only place where dma->txrunning gets cleared. If the transaction is canceled and the callback never runs, then dma->txrunning will never get cleared and we will never schedule new TX DMA transactions again.
This change makes it so we clear dma->txrunning after we terminate the DMA transaction. This is "safe" because serial8250txdmaflush is holding the UART port lock. The first thing the callback does is also grab the UART port lock, so access to dma->txrunning is serialized.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43061?
CVE-2026-43061 has been classified as a high severity vulnerability due to potential TX deadlock issues affecting DMA in the Linux kernel.
How do I fix CVE-2026-43061?
To resolve CVE-2026-43061, apply the latest patches or updates provided by the Linux Foundation for the affected Linux kernel versions.
What systems are affected by CVE-2026-43061?
CVE-2026-43061 affects systems running the Linux kernel with the 8250 serial driver that utilizes DMA.
What are the risks associated with CVE-2026-43061?
The risks associated with CVE-2026-43061 include potential system hangs or crashes due to TX deadlocks in serial communication.
Has CVE-2026-43061 been reported in any exploits?
As of now, there are no public reports of active exploits specifically targeting CVE-2026-43061.