From b59e139bbd5c789700aa9cefe7eb6590bc516b86 Mon Sep 17 00:00:00 2001 From: YOSHIFUJI Hideaki Date: Fri, 30 Mar 2007 14:45:35 -0700 Subject: [PATCH] [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 --- net/ipv6/raw.c | 4 ++-- net/ipv6/udp.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 306d5d8..203e069 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -687,9 +687,9 @@ 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 0ad4719..f590db5 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -615,7 +615,7 @@ 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; -- 1.8.2.3