Re: [RFC PATCH 2/9] audit,io_uring,io-wq: add some basic audit support to io_uring

Pavel Begunkov
2021-06-02T08:27:04Z

On 5/28/21 5:02 PM, Paul Moore wrote:
> On Wed, May 26, 2021 at 4:19 PM Paul Moore <paul@paul-moore.com> wrote:
>> ... If we moved the _entry
>> and _exit calls into the individual operation case blocks (quick
>> openat example below) so that only certain operations were able to be
>> audited would that be acceptable assuming the high frequency ops were
>> untouched? My initial gut feeling was that this would involve >50% of
>> the ops, but Steve Grubb seems to think it would be less; it may be
>> time to look at that a bit more seriously, but if it gets a NACK
>> regardless it isn't worth the time - thoughts?
>>
>> case IORING_OP_OPENAT:
>> audit_uring_entry(req->opcode);
>> ret = io_openat(req, issue_flags);
>> audit_uring_exit(!ret, ret);
>> break;
>
> I wanted to pose this question again in case it was lost in the
> thread, I suspect this may be the last option before we have to "fix"
> things at the Kconfig level. I definitely don't want to have to go
> that route, and I suspect most everyone on this thread feels the same,
> so I'm hopeful we can find a solution that is begrudgingly acceptable
> to both groups.

May work for me, but have to ask how many, and what is the
criteria? I'd think anything opening a file or manipulating fs:

IORING_OP_ACCEPT, IORING_OP_CONNECT, IORING_OP_OPENAT[2],
IORING_OP_RENAMEAT, IORING_OP_UNLINKAT, IORING_OP_SHUTDOWN,
IORING_OP_FILES_UPDATE
+ coming mkdirat and others.

IORING_OP_CLOSE? IORING_OP_SEND IORING_OP_RECV?

What about?
IORING_OP_FSYNC, IORING_OP_SYNC_FILE_RANGE,
IORING_OP_FALLOCATE, IORING_OP_STATX,
IORING_OP_FADVISE, IORING_OP_MADVISE,
IORING_OP_EPOLL_CTL

Another question, io_uring may exercise asynchronous paths,
i.e. io_issue_sqe() returns before requests completes.
Shouldn't be the case for open/etc at the moment, but was that
considered?

I don't see it happening, but would prefer to keep it open
async reimplementation in a distant future. Does audit sleep?

--
Pavel Begunkov