> On 28. Feb 2021, at 13:27, dmilith . <dmilith_at_gmail.com> wrote: > > First of all - ALSR is designed as mitigation for external attacks, > not internal ones (logged in user). > Second - Linux and FreeBSD both have weak implementations in > comparison to PAX-driven ones. Try attacking the system with > Grsecurity or HardenedBSD (both use the strongest ASLR available > AFAIK). > > Saying that security mitigation features that affect no performance > are "meaningless", is just ridiculous or at least just irresponsible. > It's like telling C programmers that stack protection or out of bounds > checks are bad, cause there's nothing wrong with random SEGFAULTS from > time to time… > You seem to forget that those mechanisms are there exactly because programmers are not caring about random faults from time to time:D With correct code, one would not need mechanisms like ALSR. rgds, toomas > > On 28/02/2021, Ihor Antonov <ihor_at_antonovs.family> wrote: >> On 2021-02-27 22:29, Warner Losh wrote: >>> On Sat, Feb 27, 2021 at 9:34 PM Ihor Antonov <ihor_at_antonovs.family> >>> wrote: >>> >>>>> >>>>> But isn't it well-known that ASLR/ASR/any-related-buzzwork does not >>>>> add >>>>> any security, except imaginary? The only purpose of it is to have a >>>>> check-list item ticked green. >>>> >>>> I don't know if I should parse this as sarcasm (or any other form of >>>> "humor") or is a serious statement? But this does leave me with a whole >>>> bunch of questions.. >>>> >>>> If this is really how Konstantin is describing it then is it OK to say >>>> about this to the whole Internet? Why FreeBSD Foundation is paying for >>>> meaningless work then? Why members of the Core team do this work? Does >>>> this mean that FreeBSD is working to satisfy the silly needs of some >>>> fat >>>> customer? What about project independence and not being controlled by >>>> big money? >>>> >>>> Where can I read about ASLR and security myths? >>> >>> Why not spend time and explain why this does not work? >>>> >>> >>> Not to rise to the baitiness of all these leading questions (they really >>> are quite contrary to how our community usually comports itself, but for >>> the sake of civil discourse, I'll ignore).... >>> >>> I'll bet it has something to do with the many known ASLR attacks. One is >>> chronicled in https://www.vusec.net/projects/anc/ and elsewhere, which >>> show >>> how MMU side channels can defeat ASLR. Or maybe he's familiar with the >>> offset2lib attack against Linux 64-bit ASLR documented in this paper >>> https://cybersecurity.upv.es/attacks/offset2lib/offset2lib-paper.pdf. >>> There's many others as well that show the shortcomings of ASLR and >>> disclose >>> ways to defeat it using various clever means. >> >> Warner, thanks for the links. They are indeed interesting. >> >>>> You clearly should mean something useful and much more important than >>>> that, >>> >>> Maybe he'd like to understand how PIE accomplishes better security give >>> the >>> known ASLR weaknesses. And rather than take a sarcastic tone, he asked >>> for >>> more details that back up the earlier claims of improved security so we >>> could all learn something. >> >> The conclusion of the paper in the second link clearly says: >> >> We present a new weakness on the current implementationof the ASLR >> Linux systems which affects PIE compiled ex-ecutables. Applications >> compiled with PIE are consideredto be more robust since it makes >> attacks more difficult. >> >> Which I read as ASLR and PIE work better together. This is the same what >> Gordon was saying. >> >> The whole situation is wrong on 2 different levels. >> >> First: saying that ASLR is not perfect and can be broken is not the same >> thing as saying "The only purpose of it is to have a check-list item ticked >> green" >> >> There are no perfect security measures, and you guys (kernel and OS >> developers) should know that better than us (users). Hackers find new >> exploits, developers find ways to mitigate them and cycle repeats. Just >> the fact that ASLR can be broken is not the reason to not have it. >> >> Second: look at this exchange from a distance >> >> Ed: we are enabling security feature X, please rebuild your worlds.. >> Godron: great progress! go team! >> Konstantin: why do you think this is great progress? (implying it is >> not) >> Gordon: well, I heard feature X works best with feature Y >> Konstantin: feature Y is useless checkbox, next time you speak make sure >> you say something useful! >> >> Considering the fact that Konstantin himself worked on ASLR this is at >> least confusing.. Also does this also mean that feature X (PIE) is also >> useless checkbox? >> >> Konstantin, Ed, Warner - I dunno what is going on in your house (Core) but >> it does not look good form the outside. You are sending mixed signals to >> your auditory. >> >> >> _______________________________________________ >> freebsd-current_at_freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-current >> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org" >> > > > -- > -- > Daniel Dettlaff > Versatile Knowledge Systems > verknowsys.com > _______________________________________________ > freebsd-current_at_freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org"Received on Sun Feb 28 2021 - 11:23:41 UTC
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