From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Thu, 05 Aug 2010 10:19:38 +0000 Subject: Re: [patch] isdn: fix information leak Message-Id: <20100805101938.GH9031@bicker> List-Id: References: <20100805093806.GF9031@bicker> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: Changli Gao Cc: Karsten Keil , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org On Thu, Aug 05, 2010 at 06:08:08PM +0800, Changli Gao wrote: > On Thu, Aug 5, 2010 at 5:38 PM, Dan Carpenter wrote: > > The main motivation of this patch changing strcpy() to strlcpy(). > > We strcpy() to copy a 48 byte buffers into a 49 byte buffers. =A0So at > > best the last byte has leaked information, or maybe there is an > > overflow? =A0Anyway, this patch closes the information leaks by zeroing > > the memory and the calls to strlcpy() prevent overflows. >=20 > strlcpy() can handle the terminator NUL. so you don't need to zero it. If there are no NUL chars in "rcvmsg->msg_data.byte_array" then strlcpy() is sufficient, but if there is a NUL character then you need to zero the memory. The patch handles both possibilities. regards, dan carpenter -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html