From: Shang XiaoJing <shangxiaojing@huawei.com>
Date: Thu, 17 Nov 2022 02:45:14 +0000 (+0800)
Subject: parisc: led: Fix potential null-ptr-deref in start_task()
X-Git-Tag: v6.1.8~604
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=67c98fec87ed76b1feb2ae810051afd88dfa9df6;p=platform%2Fkernel%2Flinux-starfive.git

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: 3499495205a6 ("[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>
---

diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index d4be9d2..8bdc5e0 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -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;