In bpf_tcp_recvmsg() we first took a reference on the psock, however
once we find that there are skbs in the normal socket's receive queue
we return with processing them through tcp_recvmsg(). Problem is that
we leak the taken reference on the psock in that path. Given we don't
really do anything with the psock at this point, move the skb_queue_empty()
test before we fetch the psock to fix this case.
Fixes: 8934ce2fd081 ("bpf: sockmap redirect ingress support")
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
---
kernel/bpf/sockmap.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 01879e4..26d8a30 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -912,6 +912,8 @@ static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr
*msg, size_t len,
if (unlikely(flags & MSG_ERRQUEUE))
return inet_recv_error(sk, msg, len, addr_len);
+ if (!skb_queue_empty(&sk->sk_receive_queue))
+ return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
rcu_read_lock();
psock = smap_psock_sk(sk);
@@ -922,9 +924,6 @@ static int bpf_tcp_recvmsg(struct sock *sk, struct msghdr
*msg, size_t len,
goto out;
rcu_read_unlock();
- if (!skb_queue_empty(&sk->sk_receive_queue))
- return tcp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
-
lock_sock(sk);
bytes_ready:
while (copied != len) {
--
2.9.5
