On 5/26/24 11:19 PM, Li RongQing wrote:
> I think when the description is freed, it maybe used again because of
s/description/descriptor/
> 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.
>
> Signed-off-by: Li RongQing <lirongqing@xxxxxxxxx>
> ---
> 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.
I see what you are pointing at. I think you will also need a
list_del(&desc->list);
immediately after the comments.
Because if the descriptor is freed and given out to a different thread while the code is still walking the list, the iterator may hit a bad pointer due to the freed descriptor pointing to something else.
Also, please include a Fixes tag for the fix. Thanks!
