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Message-ID: <9a1d96ae-23eb-b979-5c85-ffff057f5e5f@opensource.cirrus.com>
Date:   Tue, 16 May 2023 18:14:03 +0100
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Subject: Re: [PATCH 1/5] debugfs: Prevent NULL dereference reading from string
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To:     <gregkh@linuxfoundation.org>, <rafael@kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <patches@opensource.cirrus.com>
References: <20230516160753.32317-1-rf@opensource.cirrus.com>
 <20230516160753.32317-2-rf@opensource.cirrus.com>
From:   Richard Fitzgerald <rf@opensource.cirrus.com>
In-Reply-To: <20230516160753.32317-2-rf@opensource.cirrus.com>
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On 16/5/23 17:07, Richard Fitzgerald wrote:
> --- a/fs/debugfs/file.c
> +++ b/fs/debugfs/file.c
> @@ -878,6 +878,9 @@ ssize_t debugfs_read_file_str(struct file *file, char __user *user_buf,
>   		return ret;
>   
>   	str = *(char **)file->private_data;
> +	if (!str)
> +		return simple_read_from_buffer(user_buf, count, ppos, "\n", 1);
> +

Oh, this isn't right. I've somehow sent an older version that is missing
the call to debugfs_file_put(). Sorry. I'll send a v2 chain.