| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.8 181/186] mm/migrate: fixup setting UFFD_WP flag | Date | Tue, 8 Sep 2020 17:25:23 +0200 |
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From: Alistair Popple <alistair@popple.id.au>
commit ebdf8321eeeb623aed60f7ed16f7445363230118 upstream.
Commit f45ec5ff16a75 ("userfaultfd: wp: support swap and page migration") introduced support for tracking the uffd wp bit during page migration. However the non-swap PTE variant was used to set the flag for zone device private pages which are a type of swap page.
This leads to corruption of the swap offset if the original PTE has the uffd_wp flag set.
Fixes: f45ec5ff16a75 ("userfaultfd: wp: support swap and page migration") Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Peter Xu <peterx@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Link: https://lkml.kernel.org/r/20200825064232.10023-1-alistair@popple.id.au Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/migrate.c +++ b/mm/migrate.c @@ -251,7 +251,7 @@ static bool remove_migration_pte(struct entry = make_device_private_entry(new, pte_write(pte)); pte = swp_entry_to_pte(entry); if (pte_swp_uffd_wp(*pvmw.pte)) - pte = pte_mkuffd_wp(pte); + pte = pte_swp_mkuffd_wp(pte); } }
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