diff options
| author | Joe Stringer | 2020-04-07 20:35:40 -0700 |
|---|---|---|
| committer | Daniel Borkmann | 2020-04-09 01:02:14 +0200 |
| commit | 8e368dc72e86ad1e1a612416f32d5ad22dca88bc (patch) | |
| tree | 654cd7e341b07cb25b2a1b224d7c900f26ebce91 /net | |
| parent | eb203f4b89c1a1a779d9781e49b568d2a712abc6 (diff) | |
bpf: Fix use of sk->sk_reuseport from sk_assign
In testing, we found that for request sockets the sk->sk_reuseport field
may yet be uninitialized, which caused bpf_sk_assign() to randomly
succeed or return -ESOCKTNOSUPPORT when handling the forward ACK in a
three-way handshake.
Fix it by only applying the reuseport check for full sockets.
Fixes: cf7fbe660f2d ("bpf: Add socket assign support")
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200408033540.10339-1-joe@wand.net.nz
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/filter.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 7628b947dbc3..7d6ceaa54d21 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5925,7 +5925,7 @@ BPF_CALL_3(bpf_sk_assign, struct sk_buff *, skb, struct sock *, sk, u64, flags) return -EOPNOTSUPP; if (unlikely(dev_net(skb->dev) != sock_net(sk))) return -ENETUNREACH; - if (unlikely(sk->sk_reuseport)) + if (unlikely(sk_fullsock(sk) && sk->sk_reuseport)) return -ESOCKTNOSUPPORT; if (sk_is_refcounted(sk) && unlikely(!refcount_inc_not_zero(&sk->sk_refcnt))) |