Re: [syzbot] WARNING in p9_client_destroy

[Vlastimil Babka]

On 7/24/22 15:17, syzbot wrote:
> syzbot has bisected this issue to:
> 
> commit 7302e91f39a81a9c2efcf4bc5749d18128366945
> Author: Marco Elver <elver@xxxxxxxxxx>
> Date:   Fri Jan 14 22:03:58 2022 +0000
> 
>     mm/slab_common: use WARN() if cache still has objects on destroy

Just to state the obvious, bisection pointed to a commit that added the
warning, but the reason for the warning would be that p9 is destroying a
kmem_cache without freeing all the objects there first, and that would be
true even before the commit.

> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=142882ce080000
> start commit:   cb71b93c2dc3 Add linux-next specific files for 20220628
> git tree:       linux-next
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=162882ce080000
> console output: https://syzkaller.appspot.com/x/log.txt?x=122882ce080000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb
> dashboard link: https://syzkaller.appspot.com/bug?extid=5e28cdb7ebd0f2389ca4
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=156f74ee080000
> 
> Reported-by: syzbot+5e28cdb7ebd0f2389ca4@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 7302e91f39a8 ("mm/slab_common: use WARN() if cache still has objects on destroy")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection