RE: [PATCH 1/1] io_uring: prevent opcode speculation

[lizetao <lizetao1@huawei.com>]

Hi,

> -----Original Message-----
> From: Pavel Begunkov <asml.silence@gmail.com>
> Sent: Saturday, February 15, 2025 6:48 AM
> To: io-uring@vger.kernel.org
> Cc: asml.silence@gmail.com
> Subject: [PATCH 1/1] io_uring: prevent opcode speculation
> 
> sqe->opcode is used for different tables, make sure we santitise it
> against speculations.
> 
> Cc: stable@vger.kernel.org
> Fixes: d3656344fea03 ("io_uring: add lookup table for various opcode needs")
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
>  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
> 263e504be4a8..29a42365a481 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -2045,6 +2045,8 @@ static int io_init_req(struct io_ring_ctx *ctx, struct
> io_kiocb *req,
>  		req->opcode = 0;
>  		return io_init_fail_req(req, -EINVAL);
>  	}
> +	opcode = array_index_nospec(opcode, IORING_OP_LAST);
> +
>  	def = &io_issue_defs[opcode];
>  	if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) {
>  		/* enforce forwards compatibility on users */
> --
> 2.48.1
> 

Reviewed-by: Li Zetao <lizetao1@huawei.com>

---
Li Zetao