Ignore the old date...
Jason, is this good to go?
Steve.
On 8/31/2018 9:16 AM, Steve Wise wrote:
> Currently a uverbs completion event queue is flushed of events in
> ib_uverbs_comp_event_close() with the queue spinlock held and then
> released. Yet setting ev_queue->is_closed is not set until later in
> uverbs_hot_unplug_completion_event_file().
>
> In between the time ib_uverbs_comp_event_close() releases the lock
> and uverbs_hot_unplug_completion_event_file() acquires the lock, a
> completion event can arrive and be inserted into the event queue by
> ib_uverbs_comp_handler().
>
> This can cause a "double add" list_add warning or crash depending on
> the kernel configuration, or a memory leak because the event is never
> dequeued since the queue is already closed down.
>
> So add setting ev_queue->is_closed = 1 to ib_uverbs_comp_event_close().
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 1e7710f3f656 ("IB/core: Change completion channel to use the reworked objects schema")
> Signed-off-by: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
> ---
>
> Changes since v1:
>
> leave setting ev_queue.is_closed to 1 in
> uverbs_hot_unplug_completion_event_file().
>
> ---
> drivers/infiniband/core/uverbs_main.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
> index 823beca448e1..b3ef7db68bde 100644
> --- a/drivers/infiniband/core/uverbs_main.c
> +++ b/drivers/infiniband/core/uverbs_main.c
> @@ -440,6 +440,7 @@ static int ib_uverbs_comp_event_close(struct inode *inode, struct file *filp)
> list_del(&entry->obj_list);
> kfree(entry);
> }
> + file->ev_queue.is_closed = 1;
> spin_unlock_irq(&file->ev_queue.lock);
>
> uverbs_close_fd(filp);
>
