CVE-2026-43061

A flaw was found in the Linux kernel's 8250 serial driver when utilizing Direct Memory Access (DMA). An issue arises when a DMA transaction is terminated asynchronously, as the system may not properly clear the dma->tx_running flag. This prevents subsequent transmit (TX) DMA transactions from being scheduled, leading to a deadlock. This vulnerability can result in a Denial of Service (DoS), rendering the serial communication unresponsive.

This vulnerability is rated as Moderate because exploitation requires local system access to interact with serial ports, and the resulting impact is limited to a denial of service on affected serial communications. Under typical Red Hat Enterprise Linux server deployments, standard serial interfaces rarely rely on asynchronous DMA channels, substantially constraining widespread exposure. Furthermore, the issue only affects transmission over the active UART channel without causing an unrecoverable kernel panic or compromising system confidentiality or integrity.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.