On Mon, Sep 18, 2023 at 12:00:24PM +0200, David Hildenbrand wrote: > > If you want syzbot to run the reproducer, reply with: > > #syz test: git://repo/address.git branch-or-commit-hash > > If you attach or paste a git patch, syzbot will apply it before testing. If I understand correctly, you have to do it like this: #syz test diff --git a/mm/rmap.c b/mm/rmap.c index 789a2beb8b3a..f13a2927163d 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1249,8 +1249,10 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, } if (flags & RMAP_EXCLUSIVE) SetPageAnonExclusive(page); - VM_WARN_ON_FOLIO(page_mapcount(page) > 1 && PageAnonExclusive(page), - folio); + /* While PTE-mapping a THP we have a PMD and a PTE mapping. */ + VM_WARN_ON_FOLIO((atomic_read(&page->_mapcount) > 0 || + (folio_test_large(folio) && folio_entire_mapcount(folio) > 1)) && + PageAnonExclusive(page), folio); mlock_vma_folio(folio, vma, compound); } --
