Commit 5e450045 authored Nov 17, 2022 by Shang XiaoJing Committed by Greg Kroah-Hartman Jan 18, 2023

parisc: led: Fix potential null-ptr-deref in start_task()



commit 41f563ab3c33698bdfc3403c7c2e6c94e73681e4 upstream.

start_task() calls create_singlethread_workqueue() and not checked the
ret value, which may return NULL. And a null-ptr-deref may happen:

start_task()
    create_singlethread_workqueue() # failed, led_wq is NULL
    queue_delayed_work()
        queue_delayed_work_on()
            __queue_delayed_work()  # warning here, but continue
                __queue_work()      # access wq->flags, null-ptr-deref

Check the ret value and return -ENOMEM if it is NULL.

Fixes: 34994952 ("[PARISC] Use work queue in LED/LCD driver instead of tasklet.")
Signed-off-by: Shang XiaoJing <shangxiaojing@huawei.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 662dc7c6

drivers/parisc/led.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -137,6 +137,9 @@ static int start_task(void)

		/* Create the work queue and queue the LED task */
		led_wq = create_singlethread_workqueue("led_wq");
		if (!led_wq)
		return -ENOMEM;

		queue_delayed_work(led_wq, &led_task, 0);

		return 0;