diff options
| author | Lokesh Gidra <lokeshgidra@google.com> | 2024-04-04 20:17:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-27 18:12:54 +0300 |
| commit | df5f6e683e7f21a15d8be6e7a0c7a46436963ebe (patch) | |
| tree | 2243d17989eeb662f8dc3dcf22b6d3dc3e87306e | |
| parent | 6bf32da0e288008bbee72036ebf2c68b9f66bc1e (diff) | |
| download | linux-df5f6e683e7f21a15d8be6e7a0c7a46436963ebe.tar.xz | |
userfaultfd: change src_folio after ensuring it's unpinned in UFFDIO_MOVE
commit c0205eaf3af9f5db14d4b5ee4abacf4a583c3c50 upstream.
Commit d7a08838ab74 ("mm: userfaultfd: fix unexpected change to src_folio
when UFFDIO_MOVE fails") moved the src_folio->{mapping, index} changing to
after clearing the page-table and ensuring that it's not pinned. This
avoids failure of swapout+migration and possibly memory corruption.
However, the commit missed fixing it in the huge-page case.
Link: https://lkml.kernel.org/r/20240404171726.2302435-1-lokeshgidra@google.com
Fixes: adef440691ba ("userfaultfd: UFFDIO_MOVE uABI")
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | mm/huge_memory.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 94c958f7ebb5..6790f93fda45 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2244,9 +2244,6 @@ int move_pages_huge_pmd(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, pm goto unlock_ptls; } - folio_move_anon_rmap(src_folio, dst_vma); - WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr)); - src_pmdval = pmdp_huge_clear_flush(src_vma, src_addr, src_pmd); /* Folio got pinned from under us. Put it back and fail the move. */ if (folio_maybe_dma_pinned(src_folio)) { @@ -2255,6 +2252,9 @@ int move_pages_huge_pmd(struct mm_struct *mm, pmd_t *dst_pmd, pmd_t *src_pmd, pm goto unlock_ptls; } + folio_move_anon_rmap(src_folio, dst_vma); + WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr)); + _dst_pmd = mk_huge_pmd(&src_folio->page, dst_vma->vm_page_prot); /* Follow mremap() behavior and treat the entry dirty after the move */ _dst_pmd = pmd_mkwrite(pmd_mkdirty(_dst_pmd), dst_vma); |