@@ -1757,7 +1757,6 @@ static int atmel_startup(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
- struct tty_struct *tty = port->state->port.tty;
int retval;
/*
@@ -1772,8 +1771,8 @@ static int atmel_startup(struct uart_port *port)
* Allocate the IRQ
*/
retval = request_irq(port->irq, atmel_interrupt,
- IRQF_SHARED | IRQF_COND_SUSPEND,
- tty ? tty->name : "atmel_serial", port);
+ IRQF_SHARED | IRQF_COND_SUSPEND,
+ dev_name(&pdev->dev), port);
if (retval) {
dev_err(port->dev, "atmel_startup - Can't get irq\n");
return retval;
I was puzzled while looking at /proc/interrupts and random things showed up between reboots. This occurred more often but I realised it later. The "correct" output should be: |38: 11861 atmel-aic5 2 Level ttyS0 but I saw sometimes |38: 6426 atmel-aic5 2 Level tty1 and accounted it wrongly as correct. This is use after free and the former example randomly got the "old" pointer which pointed to the same content. With SLAB_FREELIST_RANDOM and HARDENED I even got |38: 7067 atmel-aic5 2 Level E=Started User Manager for UID 0 or other nonsense. As it turns out the tty, pointer that is accessed in atmel_startup(), is freed() before atmel_shutdown(). It seems to happen quite often that the tty for ttyS0 is allocated and freed while ->shutdown is not invoked. I don't do anything special - just a systemd boot :) Use dev_name(&pdev->dev) as the IRQ name for request_irq(). This exists as long as the driver is loaded so no use-after-free here. Cc: stable@vger.kernel.org Fixes: 761ed4a94582 ("tty: serial_core: convert uart_close to use tty_port_close") Acked-by: Richard Genoud <richard.genoud@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- v2…v3: - Add Acked-by - replace port->name -> dev_name(&pdev->dev) to ease work for backporters (suggested by Rob) v1…v2: add Fixes after bisect. drivers/tty/serial/atmel_serial.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)