io_uring: Fix ->data corruption on re-enqueue

work->data and work->list are shared in union. io_wq_assign_next() sets
->data if a req having a linked_timeout, but then io-wq may want to use
work->list, e.g. to do re-enqueue of a request, so corrupting ->data.

->data is not necessary, just remove it and extract linked_timeout
through @link_list.

Fixes: 60cf46ae60 ("io-wq: hash dependent work")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-03-23 00:23:29 +03:00 committed by Jens Axboe
parent f2cf11492b
commit 18a542ff19
2 changed files with 5 additions and 9 deletions

View File

@ -63,10 +63,7 @@ static inline void wq_node_del(struct io_wq_work_list *list,
} while (0)
struct io_wq_work {
union {
struct io_wq_work_node list;
void *data;
};
struct io_wq_work_node list;
void (*func)(struct io_wq_work **);
struct files_struct *files;
struct mm_struct *mm;

View File

@ -1567,9 +1567,10 @@ static void io_free_req(struct io_kiocb *req)
static void io_link_work_cb(struct io_wq_work **workptr)
{
struct io_wq_work *work = *workptr;
struct io_kiocb *link = work->data;
struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
struct io_kiocb *link;
link = list_first_entry(&req->link_list, struct io_kiocb, link_list);
io_queue_linked_timeout(link);
io_wq_submit_work(workptr);
}
@ -1584,10 +1585,8 @@ static void io_wq_assign_next(struct io_wq_work **workptr, struct io_kiocb *nxt)
*workptr = &nxt->work;
link = io_prep_linked_timeout(nxt);
if (link) {
if (link)
nxt->work.func = io_link_work_cb;
nxt->work.data = link;
}
}
/*