neigh: fix rcu splat in neigh_update()

[mirror_ubuntu-bionic-kernel.git] / net / core / neighbour.c

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 43449649cf732c3e28a68de22f3aac92ff6163ba..909ecb3c2a3344077332bfc9fb66fd7f0bfa8031 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1168,10 +1168,14 @@ int neigh_update(struct neighbour *neigh, const u8 *lladdr, u8 new,
                        struct dst_entry *dst = skb_dst(skb);
                        struct neighbour *n2, *n1 = neigh;
                        write_unlock_bh(&neigh->lock);
+
+                       rcu_read_lock();
                        /* On shaper/eql skb->dst->neighbour != neigh :( */
                        if (dst && (n2 = dst_get_neighbour(dst)) != NULL)
                                n1 = n2;
                        n1->output(n1, skb);
+                       rcu_read_unlock();
+
                        write_lock_bh(&neigh->lock);
                }
                skb_queue_purge(&neigh->arp_queue);