5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ming Lei ming.lei@redhat.com
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 axboe@kernel.dk Fixes: 2b188cc1bb85 ("Add io_uring IO interface") Cc: stable@vger.kernel.org Signed-off-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20240510035031.78874-2-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/io_uring.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -6621,6 +6621,8 @@ static int io_req_prep(struct io_kiocb * { 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: