Re: [syzbot] kernel BUG in hugepage_add_anon_rmap

From: Aleksandr Nogikh
Date: Tue Mar 01 2022 - 12:41:42 EST


On Tue, Mar 1, 2022 at 6:33 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, 01 Mar 2022 05:57:27 -0800 syzbot <syzbot+d7ed29a6231d3747fb31@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 196d330d7fb1 Add linux-next specific files for 20220222
>
> This seems to be a relatively old kernel?

Yes, syzbot was unfortunately unable to switch to the newer linux-next
versions for several days because they triggered the "WARNING in
__mod_memcg_lruvec_state" error during boot.
https://syzkaller.appspot.com/bug?id=f7421a1372deecbdb46bd6fb35ce84b16024b7f5

Now the problem is gone and syzbot is running the latest 20220301 version.

>
> > git tree: linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15b0618a700000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=45b71d0aea81d553
> > dashboard link: https://syzkaller.appspot.com/bug?extid=d7ed29a6231d3747fb31
> > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> >
> > Unfortunately, I don't have any reproducer for this issue yet.
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+d7ed29a6231d3747fb31@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > ------------[ cut here ]------------
> > kernel BUG at mm/rmap.c:2330!
>
> BUG_ON(!PageLocked(page)) in hugepage_add_anon_rmap()
>
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx.
> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/20220301093348.0eb7071cab3d8f0e49613fdf%40linux-foundation.org.