From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Call uart_unregister_driver() conditionally instead of
unconditionally, only if it has been previously registered.
This uses driver.state, just as the sh-sci.c driver does.
Fixes this null pointer dereference in tty_unregister_driver(),
since the 'driver' argument is null:
general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI
RIP: 0010:tty_unregister_driver+0x25/0x1d0
Fixes: 238b8721a554 ("serial uartlite driver")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Peter Korsgaard <jacmet@xxxxxxxxxx>
---
drivers/tty/serial/uartlite.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- lnx-53.orig/drivers/tty/serial/uartlite.c
+++ lnx-53/drivers/tty/serial/uartlite.c
@@ -897,7 +897,8 @@ static int __init ulite_init(void)
static void __exit ulite_exit(void)
{
platform_driver_unregister(&ulite_platform_driver);
- uart_unregister_driver(&ulite_uart_driver);
+ if (ulite_uart_driver.state)
+ uart_unregister_driver(&ulite_uart_driver);
}
module_init(ulite_init);
