Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 27 Apr 2020 19:31:34 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     youngjun <her0gyugyu@gmail.com>
Cc:     Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kernfs: fix possibility of NULL pointer dereference.
Message-ID: <20200427173134.GC3936841@kroah.com>
References: <20200427164836.48765-1-her0gyugyu@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200427164836.48765-1-her0gyugyu@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Apr 27, 2020 at 09:48:36AM -0700, youngjun wrote:
> When dentry is negative, "kernfs_dentry_node" returns NULL.
> In this case, "kernfs_root" dereferences NULL pointer.
> 
> Signed-off-by: youngjun <her0gyugyu@gmail.com>
> ---
>  fs/kernfs/dir.c | 18 ++++++++++--------
>  1 file changed, 10 insertions(+), 8 deletions(-)

And how can this be triggered on a kernfs filesystem?

thanks,

greg k-h