Re: [syzbot] kernel BUG in hugepage_add_anon_rmap

[Andrew Morton]

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?

> 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()