Re: [syzbot] [mm?] WARNING in try_to_migrate_one (3)

[Hillf Danton]

> Date: Sat, 09 Aug 2025 13:36:38 -0700	[thread overview]
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    0227b49b5027 Merge tag 'gpio-updates-for-v6.17-rc1-part2' ..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=1422d434580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2ae1da3a7f4a6ba4
> dashboard link: https://syzkaller.appspot.com/bug?extid=63859a31071a369082b1
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=117c72f0580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17ab7ea2580000

#syz test

--- x/mm/rmap.c
+++ y/mm/rmap.c
@@ -2366,6 +2366,7 @@ static bool try_to_migrate_one(struct fo
 		subpage = folio_page(folio, pfn - folio_pfn(folio));
 		address = pvmw.address;
 		anon_exclusive = folio_test_anon(folio) &&
+				 pfn == folio_pfn(folio) &&
 				 PageAnonExclusive(subpage);
 
 		if (folio_test_hugetlb(folio)) {
--