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authorLokesh Gidra <lokeshgidra@google.com>2024-04-04 10:17:26 -0700
committerAndrew Morton <akpm@linux-foundation.org>2024-04-16 15:39:48 -0700
commitc0205eaf3af9f5db14d4b5ee4abacf4a583c3c50 (patch)
tree6bebb0c72f0b247bdab5804f46b5ed8d0980b9b2 /mm
parent631426ba1d45a8672b177ee85ad4cabe760dd131 (diff)
userfaultfd: change src_folio after ensuring it's unpinned in UFFDIO_MOVE
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/huge_memory.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9859aa4f7553..89f58c7603b2 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2259,9 +2259,6 @@ 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)) {
@@ -2270,6 +2267,9 @@ 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);