From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: Re: [Patch] net: fix an array index overflow Date: Wed, 2 Dec 2009 15:24:27 +0200 Message-ID: <20091202132427.GE5224@bicker> References: <20091201082901.4678.16688.sendpatchset@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, "David S. Miller" To: Amerigo Wang Return-path: Content-Disposition: inline In-Reply-To: <20091201082901.4678.16688.sendpatchset@localhost.localdomain> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, Dec 01, 2009 at 03:26:02AM -0500, Amerigo Wang wrote: > > Don't use the address of an out-of-boundary element. > > Maybe this is not harmful at runtime, but it is still > good to improve it. > > Signed-off-by: WANG Cong > Cc: David S. Miller > It may be coincidence but my static checker smatch also complains about the code you modified. It's the wrong idea to fix code to please a checker. You end up doing things like adding an extra "return -ENOTREACHED" to silence warnings. Then the next person who writes a checker has to figure out how to seperate the unreachable code which was added to suppress gcc warnings from bits which are unreachable because of typos. Really any code that a human can read, a static checker should also be able to read. Computer programs are just state machines. At the function level they are quite small state machines. It's all logic and math which computers are very good at. So it should be fairly easy to fix the checker. ;) (The above paragraph is funnier if you knew how sucky smatch is). regards, dan carpenter > --- > diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c > index 57737b8..2669361 100644 > --- a/net/ipv4/af_inet.c > +++ b/net/ipv4/af_inet.c > @@ -1586,7 +1586,7 @@ static int __init inet_init(void) > #endif > > /* Register the socket-side information for inet_create. */ > - for (r = &inetsw[0]; r < &inetsw[SOCK_MAX]; ++r) > + for (r = &inetsw[0]; r <= &inetsw[SOCK_MAX-1]; ++r) > INIT_LIST_HEAD(r); > > for (q = inetsw_array; q < &inetsw_array[INETSW_ARRAY_LEN]; ++q)