The following call chain we can identify that dn_cache_getroute() is protected under rtnl_lock. So if we use __dev_get_by_index() instead of dev_get_by_index() to find interface handlers in it, this would help us avoid to change interface reference counter.
rtnetlink_rcv() rtnl_lock() netlink_rcv_skb() dn_cache_getroute() rtnl_unlock() Signed-off-by: Ying Xue <ying....@windriver.com> --- net/decnet/dn_route.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c index ad2efa5..22390e4 100644 --- a/net/decnet/dn_route.c +++ b/net/decnet/dn_route.c @@ -1666,12 +1666,12 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) if (fld.flowidn_iif) { struct net_device *dev; - if ((dev = dev_get_by_index(&init_net, fld.flowidn_iif)) == NULL) { + dev = __dev_get_by_index(&init_net, fld.flowidn_iif); + if (!dev) { kfree_skb(skb); return -ENODEV; } if (!dev->dn_ptr) { - dev_put(dev); kfree_skb(skb); return -ENODEV; } @@ -1693,8 +1693,6 @@ static int dn_cache_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh) err = dn_route_output_key((struct dst_entry **)&rt, &fld, 0); } - if (skb->dev) - dev_put(skb->dev); skb->dev = NULL; if (err) goto out_free; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/