Re: [syzbot] [mm?] WARNING in __folio_rmap_sanity_checks (2)

Hillf Danton
2024-12-29T00:00:42Z

On Fri, 27 Dec 2024 20:56:21 -0800
> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 8155b4ef3466 Add linux-next specific files for 20241220
> git tree: linux-next
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1652fadf980000

#syz test

--- x/mm/filemap.c
+++ y/mm/filemap.c
@@ -3636,6 +3636,7 @@ static vm_fault_t filemap_map_folio_rang
continue;
skip:
if (count) {
+ VM_WARN_ON_FOLIO(page_folio(page) != folio, folio);
set_pte_range(vmf, folio, page, count, addr);
*rss += count;
folio_ref_add(folio, count);
--