From 18a542ff19ad149fac9e5a36a4012e3cac7b3b3b Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 23 Mar 2020 00:23:29 +0300 Subject: [PATCH] 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: 60cf46ae6054 ("io-wq: hash dependent work") Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io-wq.h | 5 +---- fs/io_uring.c | 9 ++++----- 2 files changed, 5 insertions(+), 9 deletions(-) diff --git a/fs/io-wq.h b/fs/io-wq.h index 298b21f..d2a5684 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -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; diff --git a/fs/io_uring.c b/fs/io_uring.c index 05260ed..1f61ea9 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -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; - } } /* -- 2.7.4