In the Linux kernel, the following vulnerability has been resolved: tty: serial: imx: disable Ageing Timer interrupt request irq There maybe pending USR interrupt before requesting irq, however uart_add_one_port has not executed, so there will be kernel panic: [ 0.795668] Unable to handle kernel NULL pointer dereference at virtual addre ss 0000000000000080 [ 0.802701] Mem abort info: [ 0.805367] ESR = 0x0000000096000004 [ 0.808950] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.814033] SET = 0, FnV = 0 [ 0.816950] EA = 0, S1PTW = 0 [ 0.819950] FSC = 0x04: level 0 translation fault [ 0.824617] Data abort info: [ 0.827367] ISV = 0, ISS = 0x00000004 [ 0.831033] CM = 0, WnR = 0 [ 0.833866] [0000000000000080] user address but active_mm is swapper