The Linux kernel's imx serial driver had a vulnerability where imx_uart_probe() published its devm-allocated port in the imx_uart_ports[] array before uart_add_one_port() completed. If adding the port failed or after removal, the entry was not cleared, leaving a dangling pointer. This allowed a sibling probe to register the shared console through the stale entry. The issue was reproduced under KASAN on QEMU mcimx6ul-evk by unbinding and rebinding sibling UARTs and the console UART. The fix keeps the entry valid through uart_remove_one_port(), clears it properly afterward, and protects port addition/removal operations with their table updates to prevent interleaving. Duplicate-line probes reject occupied slots rather than overwriting active ports.

The vulnerability could lead to incorrect registration of UART ports, potentially causing system instability or unintended console sharing between sibling UART devices. There is no indication of remote code execution or privilege escalation. No known exploits in the wild have been reported.

A fix has been implemented in the Linux kernel to properly serialize access to imx_uart_ports[] and clear entries correctly. Users should update to the kernel version containing this fix once available. No additional mitigation is indicated.