From: Jakub Sitnicki jakub@cloudflare.com
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 jakub@cloudflare.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Martin KaFai Lau kafai@fb.com Link: https://lore.kernel.org/bpf/20220317113920.1068535-3-jakub@cloudflare.com Signed-off-by: Ovidiu Panait ovidiu.panait@windriver.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/bpf/progs/test_sock_fields.c | 4 ++++ 1 file changed, 4 insertions(+)
--- 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 *s 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))