Re: frequent lockups in 3.18rc4

From: Kirill A. Shutemov
Date: Mon Dec 01 2014 - 13:28:14 EST


On Mon, Dec 01, 2014 at 09:53:16AM -0800, Linus Torvalds wrote:
> On Mon, Dec 1, 2014 at 9:10 AM, Will Deacon <will.deacon@xxxxxxx> wrote:
> >
> > So I don't even have binfmt-misc compiled in. The two handlers I have are
> > BINFMT_ELF and BINFMT_SCRIPT, but they both check for headers that we won't
> > get back from oom_score afaict.
>
> Hmm. So I can't even get that "oom_score" file to be executable in the
> first place, which should mean that execve() should terminate very
> quickly with an EACCES error.

No idea about oom_score, but kernel happily accepts chmod on any file
under /proc/PID/net/. It caused issues before[1].

Why do we allow this?

I've asked before, but no answer so far.


[1] https://lkml.org/lkml/2014/8/2/103

--
Kirill A. Shutemov
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