From 5e4500454d75dd249be4695d83afa3ba0724c37e Mon Sep 17 00:00:00 2001 From: Shang XiaoJing Date: Thu, 17 Nov 2022 10:45:14 +0800 Subject: [PATCH] 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 Signed-off-by: Helge Deller Cc: Signed-off-by: Greg Kroah-Hartman --- drivers/parisc/led.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c index 73e37bb877a4d..609c747402d5f 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;