Re: [PATCH for-next v11 02/13] io_uring: introduce fixed buffer support for io_uring_cmd

[Jens Axboe <axboe@kernel.dk>]

On 9/29/22 6:06 AM, Anuj Gupta wrote:
> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> index 6a6d69523d75..faefa9f6f259 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -4,6 +4,7 @@
>  #include <linux/file.h>
>  #include <linux/io_uring.h>
>  #include <linux/security.h>
> +#include <linux/nospec.h>
>  
>  #include <uapi/linux/io_uring.h>
>  
> @@ -77,8 +78,21 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>  {
>  	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
>  
> -	if (sqe->rw_flags || sqe->__pad1)
> +	if (sqe->__pad1)
>  		return -EINVAL;
> +
> +	ioucmd->flags = READ_ONCE(sqe->uring_cmd_flags);

After reading this and checking for IORING_URING_CMD_FIXED, this should
have a:

	if (iocmd->flags & ~IORING_URING_CMD_FIXED)
		return -EINVAL;

to ensure we can safely add more flags in the future. Apart from that,
this looks good.

-- 
Jens Axboe