From: Kefeng Wang <wangkefeng.wang@huawei.com> mainline inclusion from mainline-v6.12-rc1 commit 58bf8c2bf47550bc94fea9cafd2bc7304d97102c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBSW1J CVE: CVE-2025-21861 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Saves a couple of calls to compound_head() and remove last two callers of putback_lru_page(). Link: https://lkml.kernel.org/r/20240826065814.1336616-5-wangkefeng.wang@huawei.co... Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com> --- mm/migrate_device.c | 41 ++++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 19 deletions(-) diff --git a/mm/migrate_device.c b/mm/migrate_device.c index 58636163731a..668c7a6b08be 100644 --- a/mm/migrate_device.c +++ b/mm/migrate_device.c @@ -821,42 +821,45 @@ void migrate_device_finalize(unsigned long *src_pfns, unsigned long i; for (i = 0; i < npages; i++) { - struct folio *dst, *src; + struct folio *dst = NULL, *src = NULL; struct page *newpage = migrate_pfn_to_page(dst_pfns[i]); struct page *page = migrate_pfn_to_page(src_pfns[i]); + if (newpage) + dst = page_folio(newpage); + if (!page) { - if (newpage) { - unlock_page(newpage); - put_page(newpage); + if (dst) { + folio_unlock(dst); + folio_put(dst); } continue; } - if (!(src_pfns[i] & MIGRATE_PFN_MIGRATE) || !newpage) { - if (newpage) { - unlock_page(newpage); - put_page(newpage); + src = page_folio(page); + + if (!(src_pfns[i] & MIGRATE_PFN_MIGRATE) || !dst) { + if (dst) { + folio_unlock(dst); + folio_put(dst); } - newpage = page; + dst = src; } - src = page_folio(page); - dst = page_folio(newpage); remove_migration_ptes(src, dst, false); folio_unlock(src); - if (is_zone_device_page(page)) - put_page(page); + if (folio_is_zone_device(src)) + folio_put(src); else - putback_lru_page(page); + folio_putback_lru(src); - if (newpage != page) { - unlock_page(newpage); - if (is_zone_device_page(newpage)) - put_page(newpage); + if (dst != src) { + folio_unlock(dst); + if (folio_is_zone_device(dst)) + folio_put(dst); else - putback_lru_page(newpage); + folio_putback_lru(dst); } } } -- 2.34.1