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From:   Ard Biesheuvel <ardb@kernel.org>
Date:   Tue, 24 Nov 2020 16:01:40 +0100
Message-ID: <CAMj1kXE3xM__pA6eaXwWV=we4sWrnecH1f7oUbuyGeHc9TPmOg@mail.gmail.com>
Subject: Re: Oops (probably) unmounting /oldroot/firmware/efi/efivars.
To:     David Laight <David.Laight@aculab.com>
Cc:     linux-efi <linux-efi@vger.kernel.org>,
        kernel list <linux-kernel@vger.kernel.org>,
        "matthew.garrett@nebula.com" <matthew.garrett@nebula.com>,
        "jk@ozlabs.org" <jk@ozlabs.org>
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On Tue, 24 Nov 2020 at 15:58, David Laight <David.Laight@aculab.com> wrote:
>
> From: Ard Biesheuvel
> > Sent: 24 November 2020 14:24
> >
> > On Tue, 24 Nov 2020 at 15:22, David Laight <David.Laight@aculab.com> wrote:
> > >
> > > I've just updated to the head of Linus's tree (5.10-rc5) and got the following
> > > 'splat' during shutdown.
> > >
> > > Userspace is Ubuntu 20.04.
> > >
> > > rc4 rebooted fine.
> > >
> > > I'll try to bisect - but it isn't quick.
> > >
> >
> > Surely caused by
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/efivarfs?id=fe5186cf12e30
> > facfe261e9be6c7904a170bd822
>
> Yep, reboots fine with that kfree() commented out.
>

Thanks for confirming.

Does it also work when keeping the kfree() and setting
inode->i_private to NULL explicitly afterwards?