On 22.02.24 22:56, Suren Baghdasaryan wrote:
On Thu, Feb 22, 2024 at 1:00 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
On Thu, 22 Feb 2024 16:08:15 +0800 Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> wrote:
After ptep_clear_flush(), if we find that src_folio is pinned we will fail
UFFDIO_MOVE and put src_folio back to src_pte entry, but the change to
src_folio->{mapping,index} is not restored in this process. This is not
what we expected, so fix it.
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
What are the expected worst-case userspace-visible runtime effects of
this flaw?
It can cause rmap for that page to be invalid. I guess memory
corruption might be the visible effect?
At least swapout+migration would no longer work, because we might fail
to locate the mappings of that folio.
Memory corruption, not sure.
--
Cheers,
David / dhildenb
