From b6920325aca03138ef9ba759ce0d4e6fbb5c9763 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 10 May 2024 11:50:27 +0800 Subject: [PATCH] io_uring: fail NOP if non-zero op flags is passed in commit 3d8f874bd620ce03f75a5512847586828ab86544 upstream. The NOP op flags should have been checked from beginning like any other opcode, otherwise NOP may not be extended with the op flags. Given both liburing and Rust io-uring crate always zeros SQE op flags, just ignore users which play raw NOP uring interface without zeroing SQE, because NOP is just for test purpose. Then we can save one NOP2 opcode. Suggested-by: Jens Axboe Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/io_uring.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 93f9ecedc59f..47bc8fe2b945 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -6474,6 +6474,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { switch (req->opcode) { case IORING_OP_NOP: + if (READ_ONCE(sqe->rw_flags)) + return -EINVAL; return 0; case IORING_OP_READV: case IORING_OP_READ_FIXED: