Re: [PATCH] serial: fix 8250 hash_mutex race and uart_get_baud_rate() divide-by-zero

From: Greg KH

Date: Sun Sep 20 2026 - 01:19:26 EST


On Sat, Sep 19, 2026 at 10:26:27PM +0000, Hui Peng wrote:
> Fix two bugs in the serial subsystem:
>
> 1. In serial8250_Label / serial_link_irq_chain() and
> serial_unlink_irq_chain() (drivers/tty/serial/8250/8250_core.c), hold
> hash_mutex across the entire IRQ list manipulation and
> request_irq()/free_irq() sequence to prevent racing IRQ chain
> insertions/removals.
> 2. In uart_get_baud_rate() and uart_set_info()
> (drivers/tty/serial/serial_core.c), avoid unsigned overflow in
> port->uartclk = new_info->baud_base * 16 and ensure the fallback
> retry in uart_get_baud_rate() terminates cleanly when no baud rate
> lies in [min, max].

Then this should be 2 different patches, right?

Please slow down.

thanks,

greg k-h