CVE-2026-89740serial: imx: serialize imx_uart_ports[] lifetime

Official description

In the Linux kernel, the following vulnerability has been resolved: serial: imx: serialize imx_uart_ports[] lifetime imx_uart_probe() publishes its devm-allocated port in imx_uart_ports[] before uart_add_one_port() because console setup uses the table. The entry is not cleared when adding the port fails or after removal, leaving a dangling pointer. A sibling probe can register the shared console through that stale entry. This was reproduced under KASAN on QEMU mcimx6ul-evk by unbinding a sibling UART, unbinding the console UART and rebinding the sibling. Keep the entry valid through uart_remove_one_port(), then clear it. Protect port addition and removal together with their table updates so sibling operations cannot interleave. Reject an occupied slot rather than clobbering an active port during a duplicate-line probe.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/ce9c074868d5c8adfb0c72de4324138d6fa1a1a8
• https://git.kernel.org/stable/c/a4acf2739434a014cdfc282175cffd3e35a97fa4
• https://git.kernel.org/stable/c/abc17fd508a511669997e48f8b014d8aa043abdf
• https://git.kernel.org/stable/c/681696ae9e4a28bdf54893c807dfe4a6c08e30a5
• https://git.kernel.org/stable/c/28b932202fcdbeb2ef58d89ce4363f480433c234
• https://git.kernel.org/stable/c/7429dce56a73bc080a8c072edb167106f73a08ae
• https://git.kernel.org/stable/c/8b0b29fdcb47907ae0296b8fe829e918e05e300f