diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2020-12-18 13:12:21 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-06 14:56:49 +0100 |
| commit | 52504a61ab999289d406f5dec930d3e3f386365d (patch) | |
| tree | 653f3219028e6adefdfda650c4d0f612ae9bf684 /fs | |
| parent | 8b8a688260b4ad39832d3fce790f2b53f1f3e535 (diff) | |
io_uring: close a small race gap for files cancel
commit dfea9fce29fda6f2f91161677e0e0d9b671bc099 upstream.
The purpose of io_uring_cancel_files() is to wait for all requests
matching ->files to go/be cancelled. We should first drop files of a
request in io_req_drop_files() and only then make it undiscoverable for
io_uring_cancel_files.
First drop, then delete from list. It's ok to leave req->id->files
dangling, because it's not dereferenced by cancellation code, only
compared against. It would potentially go to sleep and be awaken by
following in io_req_drop_files() wake_up().
Fixes: 0f2122045b946 ("io_uring: don't rely on weak ->files references")
Cc: <stable@vger.kernel.org> # 5.5+
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io_uring.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 0fcd065baa76..96598b6fbc81 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5861,15 +5861,15 @@ static void io_req_drop_files(struct io_kiocb *req) struct io_ring_ctx *ctx = req->ctx; unsigned long flags; + put_files_struct(req->work.identity->files); + put_nsproxy(req->work.identity->nsproxy); spin_lock_irqsave(&ctx->inflight_lock, flags); list_del(&req->inflight_entry); - if (waitqueue_active(&ctx->inflight_wait)) - wake_up(&ctx->inflight_wait); spin_unlock_irqrestore(&ctx->inflight_lock, flags); req->flags &= ~REQ_F_INFLIGHT; - put_files_struct(req->work.identity->files); - put_nsproxy(req->work.identity->nsproxy); req->work.flags &= ~IO_WQ_WORK_FILES; + if (waitqueue_active(&ctx->inflight_wait)) + wake_up(&ctx->inflight_wait); } static void __io_clean_op(struct io_kiocb *req) |