io_uring/net: reject SEND_VECTORIZED when unsupported

IORING_SEND_VECTORIZED with registered buffers is not implemented but
could be. Don't silently ignore the flag in this case but reject it with
an error. It only affects sendzc as normal sends don't support
registered buffers.

Fixes: 6f02527 ("io_uring/net: Allow to do vectorized send")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

io_uring/net.c

@@ -375,6 +375,8 @@ static int io_send_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 		kmsg->msg.msg_namelen = addr_len;
 	}
 	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
+		if (sr->flags & IORING_SEND_VECTORIZED)
+			return -EINVAL;
 		req->flags |= REQ_F_IMPORT_BUFFER;
 		return 0;
 	}