On 2019-11-01 11:13, Steve Grubb wrote: > 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. I don't have a problem adding auid/sessionid to /proc/<pid>/status with other related information, but it is disruptive to deprecate the existing interface which could be a seperate step. > -Steve - RGB -- Richard Guy Briggs <rgb@xxxxxxxxxx> Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635
