The quilt patch titled Subject: mm/ksm: add missing IS_ERR_OR_NULL check for stable_tree_search() has been removed from the -mm tree. Its filename was ksm-convert-cmp_and_merge_page-to-use-a-folio-fix.patch This patch was dropped because it was folded into ksm-convert-cmp_and_merge_page-to-use-a-folio.patch ------------------------------------------------------ From: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx> Subject: mm/ksm: add missing IS_ERR_OR_NULL check for stable_tree_search() Date: Thu, 24 Oct 2024 11:23:00 +0800 The stable_tree_search() maybe return -EBUSY if the stable node's page is being migrated or nullptr, we need to check kfolio with IS_ERR_OR_NULL() before dereference it. To mitigate this, add IS_ERR_OR_NULL check for stable_tree_search(). Link: https://lkml.kernel.org/r/20241024032300.2501949-1-cuigaosheng1@xxxxxxxxxx Signed-off-by: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx> Cc: Alex Shi <alexs@xxxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/ksm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/ksm.c~ksm-convert-cmp_and_merge_page-to-use-a-folio-fix +++ a/mm/ksm.c @@ -1787,7 +1787,7 @@ static __always_inline struct folio *cha * with identical content to the page that we are scanning right now. * * This function returns the stable tree node of identical content if found, - * NULL otherwise. + * -EBUSY if the stable node's page is being migrated, NULL otherwise. */ static struct folio *stable_tree_search(struct page *page) { @@ -2261,7 +2261,8 @@ static void cmp_and_merge_page(struct pa /* Start by searching for the folio in the stable tree */ kfolio = stable_tree_search(page); - if (&kfolio->page == page && rmap_item->head == stable_node) { + if (!IS_ERR_OR_NULL(kfolio) && &kfolio->page == page && + rmap_item->head == stable_node) { folio_put(kfolio); return; } _ Patches currently in -mm which might be from cuigaosheng1@xxxxxxxxxx are ksm-convert-cmp_and_merge_page-to-use-a-folio.patch