This is a note to let you know that I've just added the patch titled

serial: uartlite: fix exit path null pointer

to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From a553add0846f355a28ed4e81134012e4a1e280c2 Mon Sep 17 00:00:00 2001

From: Randy Dunlap rdunlap@infradead.org Date: Mon, 16 Sep 2019 16:12:23 -0700 Subject: serial: uartlite: fix exit path null pointer

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 --- drivers/tty/serial/uartlite.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

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);