The defect is a race condition between user-space writes to a serial terminal and the kernel printk routine. When userspace initiates an asynchronous DMA transfer to the UART, the driver releases the port lock. At the same time, the kernel printk code may seize the lock and reconfigure the UART for programmed I/O without waiting for the DMA to finish. The result is that the console driver reports that no progress has been made on the DMA engine, which causes the same message to be retransmitted repeatedly. This infinite loop consumes CPU and console bandwidth, making the system unresponsive during boot or shutdown and effectively denying legitimate console output. The vulnerability is a classic concurrency flaw, classified as CWE‑362.

The issue appears in Linux kernels that load the msm serial driver for console UARTs. All kernel versions prior to the commit that disables DMA for the console instance are affected; the exact range is not listed in the data but includes any kernels that have not applied the patch. The environment is typically embedded or mobile platforms that provide a serial console over MSM UART hardware.

No CVSS score is supplied, and the EPSS score is unavailable, so the quantitative likelihood of exploitation is unknown. The bug can only be triggered by a local process that owns a TTY device on the affected console, so it does not provide remote code execution. It is not listed in the CISA KEV catalog. The practical risk is primarily the potential for a denial‑of‑service condition during system startup or shutdown, which could be leveraged by a privileged user to disrupt system operation or mask other signs of compromise. The attack vector is inferred to be local userspace writes that coincide with kernel printk activity.