ipv6: fix double refcount of fib6_metrics

All the callers of ip6_rt_copy_init()/rt6_set_from() hold refcnt
of the "from" fib6_info, so there is no need to hold fib6_metrics
refcnt again, because fib6_metrics refcnt is only released when
fib6_info is gone, that is, they have the same life time, so the
whole fib6_metrics refcnt can be removed actually.

This fixes a kmemleak warning reported by Sabrina.

Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ec18b3ce8b6d8fc84c9bdb828448b9da88b3ed48..7208c16302f61adc15636f6a332ff0c02325cfcf 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -978,10 +978,6 @@ static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
        rt->rt6i_flags &= ~RTF_EXPIRES;
        rcu_assign_pointer(rt->from, from);
        dst_init_metrics(&rt->dst, from->fib6_metrics->metrics, true);
-       if (from->fib6_metrics != &dst_default_metrics) {
-               rt->dst._metrics |= DST_METRICS_REFCOUNTED;
-               refcount_inc(&from->fib6_metrics->refcnt);
-       }
 }
 
 /* Caller must already hold reference to @ort */