On 5/13/22 11:09, Mike Kravetz wrote: > On 5/13/22 10:26, Andrew Morton wrote: >> On Fri, 13 May 2022 09:43:24 -0700 syzbot <syzbot+acf65ca584991f3cc447@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: >> >>> syzbot has found a reproducer for the following issue on: >> >> Thanks. >> >>> HEAD commit: 1e1b28b936ae Add linux-next specific files for 20220513 >>> git tree: linux-next >>> console+strace: https://syzkaller.appspot.com/x/log.txt?x=174ae715f00000 >>> kernel config: https://syzkaller.appspot.com/x/.config?x=e4eb3c0c4b289571 >>> dashboard link: https://syzkaller.appspot.com/bug?extid=acf65ca584991f3cc447 >>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 >>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11531766f00000 >>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16ce5a9ef00000 >>> >>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>> Reported-by: syzbot+acf65ca584991f3cc447@xxxxxxxxxxxxxxxxxxxxxxxxx >>> >>> ------------[ cut here ]------------ >>> WARNING: CPU: 1 PID: 3611 at mm/hugetlb.c:6250 follow_hugetlb_page+0x1326/0x1c80 mm/hugetlb.c:6250 >> >> The try_grab_folio() added by 822951d84684d ("mm/hugetlb: Use >> try_grab_folio() instead of try_grab_compound_head()"). That commit >> has been there over a month so I guess it's something else. Does >> someone have the time to bisect? > > I can recreate in my 'easy to debug' environment, so I can bisect in > parallel with other things I need to do today. > I isolated this to Minchan Kim's "mm: fix is_pinnable_page against on cma page". Yes, the fat finger fix is in next-20220513. I don't have time to analyze right now, but can confirm that in the reproducer is_pinnable_page is returning false after this change when it previously returned true. -- Mike Kravetz
