From 1069087e2fb11f5fe61f68d83762cf01a25d8061 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Mon, 1 Aug 2022 17:57:03 +0300 Subject: [PATCH] selftests/bpf: Check dst_port only on the client socket commit 2d2202ba858c112b03f84d546e260c61425831a1 upstream. cgroup_skb/egress programs which sock_fields test installs process packets flying in both directions, from the client to the server, and in reverse direction. Recently added dst_port check relies on the fact that destination port (remote peer port) of the socket which sends the packet is known ahead of time. This holds true only for the client socket, which connects to the known server port. Filter out any traffic that is not egressing from the client socket in the BPF program that tests reading the dst_port. Fixes: 8f50f16ff39d ("selftests/bpf: Extend verifier and bpf_sock tests for dst_port loads") Signed-off-by: Jakub Sitnicki Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20220317113920.1068535-3-jakub@cloudflare.com Signed-off-by: Ovidiu Panait Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/bpf/progs/test_sock_fields.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/testing/selftests/bpf/progs/test_sock_fields.c b/tools/testing/selftests/bpf/progs/test_sock_fields.c index 3e2e3ee51cc9..43b31aa1fcf7 100644 --- a/tools/testing/selftests/bpf/progs/test_sock_fields.c +++ b/tools/testing/selftests/bpf/progs/test_sock_fields.c @@ -281,6 +281,10 @@ int read_sk_dst_port(struct __sk_buff *skb) if (!sk) RET_LOG(); + /* Ignore everything but the SYN from the client socket */ + if (sk->state != BPF_TCP_SYN_SENT) + return CG_OK; + if (!sk_dst_port__load_word(sk)) RET_LOG(); if (!sk_dst_port__load_half(sk))