Messages in this thread | | | From | Linus Torvalds <> | Date | Wed, 6 Jul 2011 11:01:47 -0700 | Subject | Re: RLIMIT_NPROC check in set_user() |
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On Wed, Jul 6, 2011 at 10:36 AM, Vasiliy Kulikov <segoon@openwall.com> wrote: > On Sun, Jun 12, 2011 at 17:09 +0400, Vasiliy Kulikov wrote: >> I'd be happy to hear opinions about improving the fixes above or >> alternative fixes. > > No comments? Even "Sigh, what a nasty problem. But we cannot really > fix it without significantly breaking the stuff. Go and drink something." ?
Thanks for reminding me.
My reaction is: "let's just remote the crazy check from set_user() entirely". If somebody has credentials to change users, they damn well have credentials to override the RLIMIT_NPROC too, and as you say, failure is likely a bigger security threat than success.
The whole point of RLIMIT_NPROC is to avoid fork-bombs. If we go over the limit for some other reason that is controlled by the super-user, who cares?
So let's keep it in kernel/fork.c where we actually create a *new* process (and where everybody knows exactly what the limit means, and people who don't check for error cases are just broken). And remove it from everywhere else.
Hmm?
Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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