| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.2 026/123] bpf: sockmap, synchronize_rcu before free'ing map | Date | Tue, 13 Aug 2019 22:09:10 -0400 |
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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); } -- 2.20.1
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