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Sender: Tejun Heo <htejun@gmail.com>
Date:   Wed, 27 Apr 2022 07:27:42 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Minchan Kim <minchan@kernel.org>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jirka Hladky <jhladky@redhat.com>,
        Thorsten Leemhuis <regressions@leemhuis.info>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        regressions@lists.linux.dev,
        Justin Forbes <jforbes@fedoraproject.org>,
        stable@vger.kernel.org
Subject: Re: [PATCH] kernfs: fix NULL dereferencing in kernfs_remove
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References: <20220427172152.3505364-1-minchan@kernel.org>
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On Wed, Apr 27, 2022 at 10:21:51AM -0700, Minchan Kim wrote:
> kernfs_remove supported NULL kernfs_node param to bail out but revent
                                                                 ^
                                                                 typo
> per-fs lock change introduced regression that dereferencing the
> param without NULL check so kernel goes crash.
> 
> This patch checks the NULL kernfs_node in kernfs_remove and if so,
> just return.
...
> Cc: stable@vger.kernel.org
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=215696
> Link: https://lore.kernel.org/lkml/CAE4VaGDZr_4wzRn2___eDYRtmdPaGGJdzu_LCSkJYuY9BEO3cw@mail.gmail.com/
> Fixes: 393c3714081a (kernfs: switch global kernfs_rwsem lock to per-fs lock)
> Reported-by: Jirka Hladky <jhladky@redhat.com>
> Tested-by: Jirka Hladky <jhladky@redhat.com>
> Signed-off-by: Minchan Kim <minchan@kernel.org>

Acked-by: Tejun Heo <tj@kernel.org>

Thanks.

-- 
tejun