From 2bb90e5cc90e1d09f631aeab041a9cf913a5bbe5 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 19 Jul 2019 10:29:20 -0700 Subject: [PATCH] bpf: sockmap, synchronize_rcu before free'ing map We need to have a synchronize_rcu before free'ing the sockmap because any outstanding psock references will have a pointer to the map and when they use this could trigger a use after free. Fixes: 604326b41a6fb ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann --- net/core/sock_map.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 28702f2e9a4a..56bcabe7c2f2 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -247,6 +247,8 @@ static void sock_map_free(struct bpf_map *map) raw_spin_unlock_bh(&stab->lock); rcu_read_unlock(); + synchronize_rcu(); + bpf_map_area_free(stab->sks); kfree(stab); } -- 2.30.2