Messages in this thread | | | Subject | Re: [PATCH 4.9] hugetlbfs: flush TLBs correctly after huge_pmd_unshare | From | Anton Ivanov <> | Date | Fri, 26 Nov 2021 18:22:30 +0000 |
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On 26/11/2021 17:49, Nadav Amit wrote: > >> On Nov 26, 2021, at 2:21 AM, Anton Ivanov <anton.ivanov@cambridgegreys.com> wrote: >> >> >> >> On 26/11/2021 06:08, Nadav Amit wrote: >>> Below is a patch to address CVE-2021-4002 [1] that I created to backport >>> to 4.9. The stable kernels of 4.14 and prior ones do not have unified >>> TLB flushing code, and I managed to mess up the arch code a couple of >>> times. >>> Now that the CVE is public, I would appreciate your review of this >>> patch. I send 4.9 for review - the other ones (4.14 and prior) are >>> pretty similar. >>> [1] https://www.openwall.com/lists/oss-security/2021/11/25/1 >>> Thanks, >>> Nadav >> >> I do not quite see the rationale for patching um >> >> It supports only standard size pages. You should not be able to map a huge page there (and hugetlbfs). >> >> I have "non-standard page size" somewhere towards the end of my queue, but it keeps falling through - not enough spare time to work on it. > > Thanks for your review. > > I did not look at the dependencies, so I did not even look if > hugetlbfs depends on !um. > > Do you prefer that for um, I will just do a BUG()? I prefer > to have a stub just to avoid potential build issues. > >
Stub will be fine.
I was just checking in case I missed something.
Brgds,
-- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/
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