Re: [PATCH 03/17] io_uring: add infra and support for IORING_OP_URING_CMD

[Jens Axboe <axboe@kernel.dk>]

On 3/10/22 6:51 PM, Luis Chamberlain wrote:
> On Tue, Mar 08, 2022 at 08:50:51PM +0530, Kanchan Joshi wrote:
>> From: Jens Axboe <axboe@kernel.dk>
>>
>> This is a file private kind of request. io_uring doesn't know what's
>> in this command type, it's for the file_operations->async_cmd()
>> handler to deal with.
>>
>> Signed-off-by: Jens Axboe <axboe@kernel.dk>
>> Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
>> ---
> 
> <-- snip -->
> 
>> +static int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
>> +{
>> +	struct file *file = req->file;
>> +	int ret;
>> +	struct io_uring_cmd *ioucmd = &req->uring_cmd;
>> +
>> +	ioucmd->flags |= issue_flags;
>> +	ret = file->f_op->async_cmd(ioucmd);
> 
> I think we're going to have to add a security_file_async_cmd() check
> before this call here. Because otherwise we're enabling to, for
> example, bypass security_file_ioctl() for example using the new
> iouring-cmd interface.
> 
> Or is this already thought out with the existing security_uring_*() stuff?

Unless the request sets .audit_skip, it'll be included already in terms
of logging. But I'd prefer not to lodge this in with ioctls, unless
we're going to be doing actual ioctls.

But definitely something to keep in mind and make sure that we're under
the right umbrella in terms of auditing and security.

-- 
Jens Axboe