Re: [PATCH] workqueue: Fix an use after free in init_rescuer()

2020-05-11 Thread Tejun Heo
On Fri, May 08, 2020 at 06:07:40PM +0300, Dan Carpenter wrote:
> We need to preserve error code before freeing "rescuer".
> 
> Fixes: f187b6974f6df ("workqueue: Use IS_ERR and PTR_ERR instead of 
> PTR_ERR_OR_ZERO.")
> Signed-off-by: Dan Carpenter 

Applied to wq/for-5.8. Thank you.

-- 
tejun


Re: [PATCH] workqueue: Fix an use after free in init_rescuer()

2020-05-10 Thread Lai Jiangshan
Reviewed-by: Lai Jiangshan 

On Fri, May 8, 2020 at 11:07 PM Dan Carpenter  wrote:
>
> We need to preserve error code before freeing "rescuer".
>
> Fixes: f187b6974f6df ("workqueue: Use IS_ERR and PTR_ERR instead of 
> PTR_ERR_OR_ZERO.")
> Signed-off-by: Dan Carpenter 
> ---
> Another option would be to just revert the original commit.
>
>  kernel/workqueue.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index ddf0537dce140..10ed8d761e0b7 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -4197,6 +4197,7 @@ static int wq_clamp_max_active(int max_active, unsigned 
> int flags,
>  static int init_rescuer(struct workqueue_struct *wq)
>  {
> struct worker *rescuer;
> +   int ret;
>
> if (!(wq->flags & WQ_MEM_RECLAIM))
> return 0;
> @@ -4208,8 +4209,9 @@ static int init_rescuer(struct workqueue_struct *wq)
> rescuer->rescue_wq = wq;
> rescuer->task = kthread_create(rescuer_thread, rescuer, "%s", 
> wq->name);
> if (IS_ERR(rescuer->task)) {
> +   ret = PTR_ERR(rescuer->task);
> kfree(rescuer);
> -   return PTR_ERR(rescuer->task);
> +   return ret;
> }
>
> wq->rescuer = rescuer;
> --
> 2.26.2
>