From: Gang Yan __tcp_read_sock() checks desc->count after each skb is consumed and breaks the loop when it reaches 0. The MPTCP variant lacks this check. This is a functional bug, other subsystems also rely on this check: TLS strparser sets desc->count to 0 once a full TLS record is assembled and depends on this break to stop reading. Add the same desc->count check to __mptcp_read_sock(), mirroring __tcp_read_sock(). Fixes: 250d9766a984 ("mptcp: implement .read_sock") Cc: stable@vger.kernel.org Co-developed-by: Geliang Tang Signed-off-by: Geliang Tang Signed-off-by: Gang Yan Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/protocol.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 7fac5fac2097..cb9515f505aa 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -4428,6 +4428,8 @@ static int __mptcp_read_sock(struct sock *sk, read_descriptor_t *desc, } mptcp_eat_recv_skb(sk, skb); + if (!desc->count) + break; } if (noack) -- 2.53.0