From: Miaohe Lin linmiaohe@huawei.com

mainline inclusion from mainline-v5.19-rc1 commit: f3b9e8cc8b09ba3b41bb068c24a1061e8a70d26f category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9K8XT CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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We can't assume pte_offset_map_lock will return same orig_pte value. So it's necessary to reacquire the orig_pte or pte_unmap_unlock will unmap the stale pte.

Link: https://lkml.kernel.org/r/20220416081416.23304-1-linmiaohe@huawei.com Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Fixes: 854e9ed09ded ("mm: support madvise(MADV_FREE)") Signed-off-by: Miaohe Lin linmiaohe@huawei.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Michal Hocko mhocko@suse.com Cc: Hugh Dickins hughd@google.com Signed-off-by: Andrew Morton akpm@linux-foundation.org

Conflicts: mm/madvise.c [Ma Wupeng: current branch dont support MADV_COLD] Signed-off-by: Ma Wupeng mawupeng1@huawei.com --- mm/madvise.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c index a3b8b7ecc930..263c2c68b0de 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -391,12 +391,12 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, if (split_huge_page(page)) { unlock_page(page); put_page(page); - pte_offset_map_lock(mm, pmd, addr, &ptl); + orig_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); goto out; } unlock_page(page); put_page(page); - pte = pte_offset_map_lock(mm, pmd, addr, &ptl); + orig_pte = pte = pte_offset_map_lock(mm, pmd, addr, &ptl); pte--; addr -= PAGE_SIZE; continue;