Commit 0a535edd authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/rw: ensure io->bytes_done is always initialized 



If IOSQE_ASYNC is set and we fail importing an iovec for a readv or
writev request, then we leave ->bytes_done uninitialized and hence the
eventual failure CQE posted can potentially have a random res value
rather than the expected -EINVAL.

Setup ->bytes_done before potentially failing, so we have a consistent
value if we fail the request early.

Cc: stable@vger.kernel.org
Reported-by: default avatarxingwei lee <xrivendell7@gmail.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 6e5e6d27

io_uring/rw.c

+7 −3
Original line number Diff line number Diff line
@@ -589,15 +589,19 @@ static inline int io_rw_prep_async(struct io_kiocb *req, int rw) 
	struct iovec *iov;

	int ret;



	iorw->bytes_done = 0;

	iorw->free_iovec = NULL;



	/* submission path, ->uring_lock should already be taken */

	ret = io_import_iovec(rw, req, &iov, &iorw->s, 0);

	if (unlikely(ret < 0))

		return ret;



	iorw->bytes_done = 0;

	if (iov) {

		iorw->free_iovec = iov;

	if (iov)

		req->flags |= REQ_F_NEED_CLEANUP;

	}



	return 0;

}