RE: [PATCH][RFC] dmaengine: idxd: Fix possible Use-After-Free in irq_process_work_list

["Li,Rongqing" <lirongqing@baidu.com>]

> I think when the description is freed, it maybe used again because of race, then
> it's next maybe pointer a value that should not be freed
> 
> To prevent this, list_for_each_entry_safe should be used.
> 

Rewrite the commit header:

    dmaengine: idxd: Fix possible Use-After-Free in irq_process_work_list

    The description has been freed in idxd_desc_complete(), should not be used
    in iteration, so replace list_for_each_entry with list_for_each_entry_safe
    to prevent the accessing

    Signed-off-by: Li RongQing <lirongqing@baidu.com>


> Signed-off-by: Li RongQing <lirongqing@baidu.com>
> ---
>  drivers/dma/idxd/irq.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c index
> 8dc029c..0c7fed7 100644
> --- a/drivers/dma/idxd/irq.c
> +++ b/drivers/dma/idxd/irq.c
> @@ -611,7 +611,7 @@ static void irq_process_work_list(struct idxd_irq_entry
> *irq_entry)
> 
>  	spin_unlock(&irq_entry->list_lock);
> 
> -	list_for_each_entry(desc, &flist, list) {
> +	list_for_each_entry_safe(desc, n, &flist, list) {
>  		/*
>  		 * Check against the original status as ABORT is software defined
>  		 * and 0xff, which DSA_COMP_STATUS_MASK can mask out.
> --
> 2.9.4