Re: [PATCH ghak90 V7 20/21] audit: add capcontid to set contid outside init_user_ns

On Friday, November 1, 2019 11:09:27 AM EDT Richard Guy Briggs wrote: > On 2019-10-31 10:50, Steve Grubb wrote: > > Hello, > > > > TLDR; I see a lot of benefit to switching away from procfs for setting > > auid & sessionid. > > > > On Wednesday, October 30, 2019 6:03:20 PM EDT Richard Guy Briggs wrote: > > > > Also, for the record, removing the audit loginuid from procfs is not > > > > something to take lightly, if at all; like it or not, it's part of > > > > the > > > > kernel API. > > > > It can also be used by tools to iterate processes related to one user or > > session. I use this in my Intrusion Prevention System which will land in > > audit user space at some point in the future. > > > > > Oh, I'm quite aware of how important this change is and it was > > > discussed > > > with Steve Grubb who saw the concern and value of considering such a > > > disruptive change. > > > > Actually, I advocated for syscall. I think the gist of Eric's idea was > > that / proc is the intersection of many nasty problems. By relying on > > it, you can't simplify the API to reduce the complexity. Almost no > > program actually needs access to /proc. ps does. But almost everything > > else is happy without it. For example, when you setup chroot jails, you > > may have to add /dev/random or / dev/null, but almost never /proc. What > > does force you to add /proc is any entry point daemon like sshd because > > it needs to set the loginuid. If we switch away from /proc, then sshd or > > crond will no longer /require/ procfs to be available which again > > simplifies the system design. > > > > > Removing proc support for auid/ses would be a > > > long-term deprecation if accepted. > > > > It might need to just be turned into readonly for a while. But then > > again, > > perhaps auid and session should be part of /proc/<pid>/status? Maybe this > > can be done independently and ahead of the container work so there is a > > migration path for things that read auid or session. TBH, maybe this > > should have been done from the beginning. > > How about making loginuid/contid/capcontid writable only via netlink but > still provide the /proc interface for reading? Deprecation of proc can > be left as a decision for later. This way sshd/crond/getty don't need > /proc, but the info is still there for tools that want to read it. This also sounds good to me. But I still think loginuid and audit sessionid should get written in /proc/<pid>/status so that all process information is consolidated in one place.

-Steve