usb: gadget: gserial: check if console kthread exists

Check for bad pointer that may result because of kthread_create failure.
This check is needed since the gserial setup callback function
(gs_console_setup()) is only freeing the info->con_buf in case of
kthread_create failure which will result into bad info->console_thread
pointer.
Without checking info->console_thread pointer validity in the
gserial_console_exit() function, before calling kthread_stop(), the
rmmod will generate Kernel Oops.

Signed-off-by: Bogdan Mirea <Bogdan-Stefan_mirea@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c
index 000677c991b0264ee079f46e79be1ab271001c9b..9b0805f55ad79b3a6b12069508ddc583d2765053 100644 (file)
--- a/drivers/usb/gadget/function/u_serial.c
+++ b/drivers/usb/gadget/function/u_serial.c
@@ -1256,7 +1256,7 @@ static void gserial_console_exit(void)
        struct gscons_info *info = &gscons_info;
 
        unregister_console(&gserial_cons);
-       if (info->console_thread != NULL)
+       if (!IS_ERR_OR_NULL(info->console_thread))
                kthread_stop(info->console_thread);
        gs_buf_free(&info->con_buf);
 }