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From:   David Laight <David.Laight@ACULAB.COM>
To:     'Alex Dewar' <alex.dewar90@gmail.com>
CC:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        "accessrunner-general@lists.sourceforge.net" 
        <accessrunner-general@lists.sourceforge.net>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] usb: atm: don't use snprintf() for sysfs attrs
Thread-Topic: [PATCH] usb: atm: don't use snprintf() for sysfs attrs
Thread-Index: AQHWemUzoPleWxCDKky1KLXQzyLa5alIeCYw
Date:   Tue, 25 Aug 2020 08:12:05 +0000
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References: <20200824222322.22962-1-alex.dewar90@gmail.com>
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From: Alex Dewar
> Sent: 24 August 2020 23:23
> kernel/cpu.c: don't use snprintf() for sysfs attrs
> 
> As per the documentation (Documentation/filesystems/sysfs.rst),
> snprintf() should not be used for formatting values returned by sysfs.
> 
> In all of these cases, sprintf() suffices as we know that the formatted
> strings will be less than PAGE_SIZE in length.

Hmmmm....
I much prefer to see bounded string ops.
sysfs really ought to be passing through the buffer length.
The buffer size should probably be SYSFS_BUF_LEN not PAGE_SIZE
(even it happens to typically be the same).
If PAGE_SIZE is big (or small) passing a 4k buffer may be
more appropriate than a PAGE_SIZE one.

	David

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