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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2018-05-07 20:11:30 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-06-16 10:52:34 +0300
commit41bdf9702caea0bfa9e578977f13a566e3fc428b (patch)
tree51804fb22d29d55972666d3212ed9ea42ba7744f /drivers/tty/serial
parent70f0a59bbdb4f7dd46255fd17060213a32af6302 (diff)
downloadlinux-41bdf9702caea0bfa9e578977f13a566e3fc428b.tar.xz
tty/serial: atmel: use port->name as name in request_irq()
commit 9594b5be7ec110ed11acec58fa94f3f293668c85 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
-rw-r--r--drivers/tty/serial/atmel_serial.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index addb287cacea..5a341b1c65c3 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1803,7 +1803,6 @@ 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;
/*
@@ -1818,8 +1817,8 @@ 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;