| From c5545d99ce3932480cd2ec6577f3da0043d2acbf Mon Sep 17 00:00:00 2001 |
| From: Randy Dunlap <rdunlap@infradead.org> |
| Date: Mon, 16 Sep 2019 16:12:23 -0700 |
| Subject: [PATCH] serial: uartlite: fix exit path null pointer |
| |
| commit a553add0846f355a28ed4e81134012e4a1e280c2 upstream. |
| |
| 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 ("[PATCH] serial uartlite driver") |
| Signed-off-by: Randy Dunlap <rdunlap@infradead.org> |
| Cc: stable <stable@vger.kernel.org> |
| Cc: Peter Korsgaard <jacmet@sunsite.dk> |
| Link: https://lore.kernel.org/r/9c8e6581-6fcc-a595-0897-4d90f5d710df@infradead.org |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c |
| index b8b912b5a8b9..06e79c11141d 100644 |
| --- a/drivers/tty/serial/uartlite.c |
| +++ b/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); |
| -- |
| 2.7.4 |
| |