Only __dev_get_by_index() is the RTNL dependant in neigh_get(). Let's replace it with dev_get_by_index_rcu() and convert RTM_GETNEIGH to RCU. Signed-off-by: Kuniyuki Iwashima --- v3: Rename err label to err_unlock --- net/core/neighbour.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index f58b534a706a6..017f41792332b 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -3049,27 +3049,29 @@ static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (!skb) return -ENOBUFS; + rcu_read_lock(); + tbl = neigh_find_table(ndm->ndm_family); if (!tbl) { NL_SET_ERR_MSG(extack, "Unsupported family in header for neighbor get request"); err = -EAFNOSUPPORT; - goto err_free_skb; + goto err_unlock; } if (nla_len(tb[NDA_DST]) != (int)tbl->key_len) { NL_SET_ERR_MSG(extack, "Invalid network address in neighbor get request"); err = -EINVAL; - goto err_free_skb; + goto err_unlock; } dst = nla_data(tb[NDA_DST]); if (ndm->ndm_ifindex) { - dev = __dev_get_by_index(net, ndm->ndm_ifindex); + dev = dev_get_by_index_rcu(net, ndm->ndm_ifindex); if (!dev) { NL_SET_ERR_MSG(extack, "Unknown device ifindex"); err = -ENODEV; - goto err_free_skb; + goto err_unlock; } } @@ -3080,28 +3082,31 @@ static int neigh_get(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (!pn) { NL_SET_ERR_MSG(extack, "Proxy neighbour entry not found"); err = -ENOENT; - goto err_free_skb; + goto err_unlock; } err = pneigh_fill_info(skb, pn, pid, seq, RTM_NEWNEIGH, 0, tbl); if (err) - goto err_free_skb; + goto err_unlock; } else { neigh = neigh_lookup(tbl, dst, dev); if (!neigh) { NL_SET_ERR_MSG(extack, "Neighbour entry not found"); err = -ENOENT; - goto err_free_skb; + goto err_unlock; } err = neigh_fill_info(skb, neigh, pid, seq, RTM_NEWNEIGH, 0); neigh_release(neigh); if (err) - goto err_free_skb; + goto err_unlock; } + rcu_read_unlock(); + return rtnl_unicast(skb, net, pid); -err_free_skb: +err_unlock: + rcu_read_unlock(); kfree_skb(skb); return err; } @@ -3904,7 +3909,7 @@ static const struct rtnl_msg_handler neigh_rtnl_msg_handlers[] __initconst = { {.msgtype = RTM_NEWNEIGH, .doit = neigh_add}, {.msgtype = RTM_DELNEIGH, .doit = neigh_delete}, {.msgtype = RTM_GETNEIGH, .doit = neigh_get, .dumpit = neigh_dump_info, - .flags = RTNL_FLAG_DUMP_UNLOCKED}, + .flags = RTNL_FLAG_DOIT_UNLOCKED | RTNL_FLAG_DUMP_UNLOCKED}, {.msgtype = RTM_GETNEIGHTBL, .dumpit = neightbl_dump_info}, {.msgtype = RTM_SETNEIGHTBL, .doit = neightbl_set}, }; -- 2.50.0.727.gbf7dc18ff4-goog