Since the features bit field has bits for internal only use as well, it may happen that the kernel exports RTAX_FEATURES attribute with zero value which is pointless.
Fix this by making sure the attribute is added only if the exported value is non-zero. Signed-off-by: Phil Sutter <p...@nwl.cc> --- net/core/rtnetlink.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 189cc78c77eba..318fc5231b2b4 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -704,6 +704,8 @@ int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics) } else if (i == RTAX_FEATURES - 1) { u32 user_features = metrics[i] & RTAX_FEATURE_MASK; + if (!user_features) + continue; BUILD_BUG_ON(RTAX_FEATURE_MASK & DST_FEATURE_MASK); if (nla_put_u32(skb, i + 1, user_features)) goto nla_put_failure; -- 2.8.2