net: ipv6: fix return value of ip6_skb_dst_mtu

commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream.

Commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.

Fixes: 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 9f7f81117434b9b43ac0d998757a0f2673a703a4..34139bc9a85380a45487ece63b47a442023bb671 100644 (file)
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -214,7 +214,7 @@ static inline bool ipv6_anycast_destination(const struct dst_entry *dst,
 int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
                 int (*output)(struct net *, struct sock *, struct sk_buff *));
 
-static inline int ip6_skb_dst_mtu(struct sk_buff *skb)
+static inline unsigned int ip6_skb_dst_mtu(struct sk_buff *skb)
 {
        struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ?
                                inet6_sk(skb->sk) : NULL;

diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
index aff901be53539a750b54eafc8be34cecf81bc558..276280d1e3dae27f9524cd2786825880337099c0 100644 (file)
--- a/net/ipv6/xfrm6_output.c
+++ b/net/ipv6/xfrm6_output.c
@@ -146,7 +146,7 @@ static int __xfrm6_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
        struct dst_entry *dst = skb_dst(skb);
        struct xfrm_state *x = dst->xfrm;
-       int mtu;
+       unsigned int mtu;
        bool toobig;
 
 #ifdef CONFIG_NETFILTER