Re: [syzbot] [mm?] WARNING in set_mm_walk

[Shakeel Butt <shakeel.butt@linux.dev>]

On Wed, Aug 12, 2026 at 02:03:58PM -0700, Andrew Morton wrote:
> On Wed, 12 Aug 2026 05:26:24 -0700 syzbot <syzbot+12ee2725d5fde63a9c96@syzkaller.appspotmail.com> wrote:
> 
> > syzbot has found a reproducer for the following issue on:
> > 
> > HEAD commit:    f5bbbfec59b4 Merge tag 'probes-fixes-v7.2-rc7' of git://gi..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=11f44c79580000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
> > dashboard link: https://syzkaller.appspot.com/bug?extid=12ee2725d5fde63a9c96
> > compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10d11149580000
> > 
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+12ee2725d5fde63a9c96@syzkaller.appspotmail.com
> > 
> > ------------[ cut here ]------------
> > current_is_kswapd()
> > WARNING: mm/vmscan.c:3800 at set_mm_walk+0x210/0x270 mm/vmscan.c:3800, CPU#2: kswapd0/111
> 
> Thanks.  Shakeel is working on a series which will fix this by removing
> the calling code.  But it isn't a minor patch.
> 
> Shakeel, it would be good to have a backportable quick-fix to make this
> warning go away?
> 

Actually the first patch [1] of the series will fix this warning and we can
backport just that patch to the older stable kernels.

Do you want me to send that patch as a standalone?

[1] https://lore.kernel.org/all/20260811203203.3456029-2-shakeel.butt@linux.dev/