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: 604326b41a ("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>
This commit is contained in:
John Fastabend 2019-07-19 10:29:20 -07:00 committed by Daniel Borkmann
parent 45a4521dcb
commit 2bb90e5cc9
1 changed files with 2 additions and 0 deletions

View File

@ -247,6 +247,8 @@ static void sock_map_free(struct bpf_map *map)
raw_spin_unlock_bh(&stab->lock); raw_spin_unlock_bh(&stab->lock);
rcu_read_unlock(); rcu_read_unlock();
synchronize_rcu();
bpf_map_area_free(stab->sks); bpf_map_area_free(stab->sks);
kfree(stab); kfree(stab);
} }