req->work might be already initialised by the time it gets into __io_arm_poll_handler(), which will corrupt it be using fields that are in an union with req->work. Luckily, the only side effect is missing put_creds(). Clean req->work before going there. Suggested-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> --- fs/io_uring.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 32b0064f806e..98e8079e67e7 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -4658,6 +4658,10 @@ static int io_poll_add(struct io_kiocb *req) struct io_poll_table ipt; __poll_t mask; + /* ->work is in union with hash_node and others */ + io_req_work_drop_env(req); + req->flags &= ~REQ_F_WORK_INITIALIZED; + INIT_HLIST_NODE(&req->hash_node); INIT_LIST_HEAD(&req->list); ipt.pt._qproc = io_poll_queue_proc; -- 2.24.0
