Date: Tue, 17 Nov 2015 23:48:55 +0100 (CET)
From: Jan Engelhardt <jengelh@inai.de>
To: David Miller <davem@davemloft.net>
cc: tj@kernel.org, pablo@netfilter.org, kaber@trash.net,
        kadlec@blackhole.kfki.hu, lizefan@huawei.com, hannes@cmpxchg.org,
        netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
        coreteam@netfilter.org, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org, kernel-team@fb.com, daniel@iogearbox.net,
        daniel.wagner@bmw-carit.de, nhorman@tuxdriver.com,
        gregkh@linuxfoundation.org
Subject: Re: [PATCH 2/5] kernfs: implement kernfs_walk_and_get()
In-Reply-To: <20151117.162040.1412296298973879057.davem@davemloft.net>
Message-ID: <alpine.LSU.2.20.1511172348110.13966@nerf40.vanv.qr>
References: <1447789240-29394-1-git-send-email-tj@kernel.org> <1447789240-29394-3-git-send-email-tj@kernel.org> <20151117.162040.1412296298973879057.davem@davemloft.net>
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On Tuesday 2015-11-17 22:20, David Miller wrote:
>> +	static char path_buf[PATH_MAX];	/* protected by kernfs_mutex */
>> +	int len = strlen(path);
> ...
>> +	if (len >= PATH_MAX)
>> +		return NULL;
>> +
>> +	memcpy(path_buf, path, len + 1);
>
>	static char path_buf[PATH_MAX];	/* protected by kernfs_mutex */
>	int len = strlcpy(path_buf, path, PATH_MAX);
> ...
>	if (len >= PATH_MAX)
>		return NULL;

	if (len < 0 || len >= PATH_MAX)

strlcpy returns a size_t, which, when coerced into an int, could lead to
negative numbers. In that sense, "size_t len" probably seems like an even
better bet yet.
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