coredump: fix race condition between collapse_huge_page() and core dumping

[thirdparty/kernel/stable.git] / mm / khugepaged.c

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a335f7c1fac428b30d7e352ebaf717e033724f74..0f741993800845399ef7a371c45f9e0a48d3bc86 100644 (file)
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1004,6 +1004,9 @@ static void collapse_huge_page(struct mm_struct *mm,
         * handled by the anon_vma lock + PG_lock.
         */
        down_write(&mm->mmap_sem);
+       result = SCAN_ANY_PROCESS;
+       if (!mmget_still_valid(mm))
+               goto out;
        result = hugepage_vma_revalidate(mm, address, &vma);
        if (result)
                goto out;