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authorJohn Fastabend <john.fastabend@gmail.com>2018-09-18 09:01:44 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2018-09-22 02:46:41 +0200
commit5607fff303636d48b88414c6be353d9fed700af2 (patch)
treebe7338b7007ecd330061ccbe9b00e339575c6f60 /kernel
parent080220b687147fd9376878534aba7194f17f6ef5 (diff)
bpf: sockmap only allow ESTABLISHED sock state
After this patch we only allow socks that are in ESTABLISHED state or are being added via a sock_ops event that is transitioning into an ESTABLISHED state. By allowing sock_ops events we allow users to manage sockmaps directly from sock ops programs. The two supported sock_ops ops are BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB and BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB. Similar to TLS ULP this ensures sk_user_data is correct. Reported-by: Eric Dumazet <edumazet@google.com> Fixes: 1aa12bdf1bfb ("bpf: sockmap, add sock close() hook to remove socks") Signed-off-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/sockmap.c31
1 files changed, 30 insertions, 1 deletions
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 488ef9663c01..1f97b559892a 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -2097,8 +2097,12 @@ static int sock_map_update_elem(struct bpf_map *map,
return -EINVAL;
}
+ /* ULPs are currently supported only for TCP sockets in ESTABLISHED
+ * state.
+ */
if (skops.sk->sk_type != SOCK_STREAM ||
- skops.sk->sk_protocol != IPPROTO_TCP) {
+ skops.sk->sk_protocol != IPPROTO_TCP ||
+ skops.sk->sk_state != TCP_ESTABLISHED) {
fput(socket->file);
return -EOPNOTSUPP;
}
@@ -2453,6 +2457,16 @@ static int sock_hash_update_elem(struct bpf_map *map,
return -EINVAL;
}
+ /* ULPs are currently supported only for TCP sockets in ESTABLISHED
+ * state.
+ */
+ if (skops.sk->sk_type != SOCK_STREAM ||
+ skops.sk->sk_protocol != IPPROTO_TCP ||
+ skops.sk->sk_state != TCP_ESTABLISHED) {
+ fput(socket->file);
+ return -EOPNOTSUPP;
+ }
+
lock_sock(skops.sk);
preempt_disable();
rcu_read_lock();
@@ -2543,10 +2557,22 @@ const struct bpf_map_ops sock_hash_ops = {
.map_check_btf = map_check_no_btf,
};
+static bool bpf_is_valid_sock_op(struct bpf_sock_ops_kern *ops)
+{
+ return ops->op == BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB ||
+ ops->op == BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB;
+}
BPF_CALL_4(bpf_sock_map_update, struct bpf_sock_ops_kern *, bpf_sock,
struct bpf_map *, map, void *, key, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
+
+ /* ULPs are currently supported only for TCP sockets in ESTABLISHED
+ * state. This checks that the sock ops triggering the update is
+ * one indicating we are (or will be soon) in an ESTABLISHED state.
+ */
+ if (!bpf_is_valid_sock_op(bpf_sock))
+ return -EOPNOTSUPP;
return sock_map_ctx_update_elem(bpf_sock, map, key, flags);
}
@@ -2565,6 +2591,9 @@ BPF_CALL_4(bpf_sock_hash_update, struct bpf_sock_ops_kern *, bpf_sock,
struct bpf_map *, map, void *, key, u64, flags)
{
WARN_ON_ONCE(!rcu_read_lock_held());
+
+ if (!bpf_is_valid_sock_op(bpf_sock))
+ return -EOPNOTSUPP;
return sock_hash_ctx_update_elem(bpf_sock, map, key, flags);
}