From: John Fastabend john.fastabend@gmail.com
[ Upstream commit 2bb90e5cc90e1d09f631aeab041a9cf913a5bbe5 ]
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 john.fastabend@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1d40e040320d2..bbc91597d8364 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -252,6 +252,8 @@ 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); }