From: YOSHIFUJI Hideaki Date: Fri, 13 Apr 2007 19:30:03 +0000 (+0200) Subject: [IPv6]: Fix incorrect length check in rawv6_sendmsg() X-Git-Tag: v2.6.16.48~5 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=889cde54cd2a82f6e4d7ed18440e0f6138b06d60;p=thirdparty%2Fkernel%2Fstable.git [IPv6]: Fix incorrect length check in rawv6_sendmsg() In article <20070329.142644.70222545.davem@davemloft.net> (at Thu, 29 Mar 2007 14:26:44 -0700 (PDT)), David Miller says: > From: Sridhar Samudrala > Date: Thu, 29 Mar 2007 14:17:28 -0700 > > > The check for length in rawv6_sendmsg() is incorrect. > > As len is an unsigned int, (len < 0) will never be TRUE. > > I think checking for IPV6_MAXPLEN(65535) is better. > > > > Is it possible to send ipv6 jumbo packets using raw > > sockets? If so, we can remove this check. > > I don't see why such a limitation against jumbo would exist, > does anyone else? > > Thanks for catching this Sridhar. A good compiler should simply > fail to compile "if (x < 0)" when 'x' is an unsigned type, don't > you think :-) Dave, we use "int" for returning value, so we should fix this anyway, IMHO; we should not allow len > INT_MAX. Signed-off-by: YOSHIFUJI Hideaki Acked-by: Sridhar Samudrala Signed-off-by: David S. Miller Signed-off-by: Adrian Bunk --- diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index ae20a0ec9bd82..5babed88b08ad 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -641,9 +641,9 @@ static int rawv6_sendmsg(struct kiocb *iocb, struct sock *sk, int err; /* Rough check on arithmetic overflow, - better check is made in ip6_build_xmit + better check is made in ip6_append_data(). */ - if (len < 0) + if (len > INT_MAX) return -EMSGSIZE; /* Mirror BSD error message compatibility */ diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 513ed8f2ac0fc..f639439e715a0 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -670,7 +670,7 @@ do_udp_sendmsg: return udp_sendmsg(iocb, sk, msg, len); /* Rough check on arithmetic overflow, - better check is made in ip6_build_xmit + better check is made in ip6_append_data(). */ if (len > INT_MAX - sizeof(struct udphdr)) return -EMSGSIZE;