Re: [syzbot] [xfs?] KASAN: slab-use-after-free Write in xlog_cil_ail_insert

From: Carlos Maiolino

Date: Thu Sep 10 2026 - 12:35:47 EST


On Thu, Sep 10, 2026 at 09:17:25PM +0530, Jeffin Philip wrote:
> On Wed, Sep 09, 2026, Dave Chinner wrote:
>
> >The short term fix is to slap a bandaid on xfs_buf_submit() to wait
> >for unpin before erroring out a pinned buffer on shutdown. That,
> >however, doesn't fix the underlying lack of full lifecycle reference
> >counts for log items.
> >
> >The long term fix is have the AIL require a reference count to be
> >held on log items it tracks, and only have that refcount removed
> >when the item is removed from the AIL. That's a much bigger rework
> >of the code.
> >
> >FYI, I've attached two document below - the design for
> >generic full lifecycle log item reference counting, and the design
> >for converting the inode log item to be dynamic similar to the buf
> >log item so we don't end up with millions of ILIs that are never
> >used left sitting around in memory until it's owner inode is
> >reclaimed.
>
> I read the documents and have started writing the wrappers. Is anyone
> else working on it?
>

I was going to as it clashes with some work I've been doing on this
area, but if you already started go for it.

> Thanks,
> Jeffin.
>