Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 25 May 2018 09:52:22 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Arnd Bergmann <arnd@arndb.de>
Cc:     "Darrick J. Wong" <darrick.wong@oracle.com>,
        linux-xfs@vger.kernel.org, Eric Sandeen <sandeen@redhat.com>,
        Martin Sebor <msebor@gmail.com>,
        Brian Foster <bfoster@redhat.com>,
        Dave Chinner <dchinner@redhat.com>,
        Eric Sandeen <sandeen@sandeen.net>,
        Dan Williams <dan.j.williams@intel.com>,
        Ross Zwisler <ross.zwisler@linux.intel.com>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] xfs: mark sb_fname as nonstring
Message-ID: <20180525165222.GA7567@infradead.org>
References: <20180525151421.2317292-1-arnd@arndb.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20180525151421.2317292-1-arnd@arndb.de>
User-Agent: Mutt/1.9.2 (2017-12-15)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
> index 84fbf164cbc3..eb79f2bc4dcc 100644
> --- a/fs/xfs/xfs_ioctl.c
> +++ b/fs/xfs/xfs_ioctl.c
> @@ -1819,12 +1819,12 @@ xfs_ioc_getlabel(
>  	BUILD_BUG_ON(sizeof(sbp->sb_fname) > FSLABEL_MAX);
>  
>  	spin_lock(&mp->m_sb_lock);
> -	strncpy(label, sbp->sb_fname, sizeof(sbp->sb_fname));
> +	strncpy(label, sbp->sb_fname, XFSLABEL_MAX);
>  	spin_unlock(&mp->m_sb_lock);

Hmm, shouldn't we just do a memcpy here?

Also given that the kernel never even looks at sb_fname maybe
we can turn into an array of unsigned chars to escape those string
warnings?