[PATCH bpf-next] bpf: explicitly prohibit ctx_{in,out} in non-skb BPF_PROG_TEST_RUN

[Stanislav Fomichev]

This should allow us later to extend BPF_PROG_TEST_RUN for non-skb case
and be sure that nobody is erroneously setting ctx_{in,out}.

Fixes: b0b9395d865e ("bpf: support input __sk_buff context in 
BPF_PROG_TEST_RUN")
Reported-by: Daniel Borkmann <dan...@iogearbox.net>
Signed-off-by: Stanislav Fomichev <s...@google.com>
---
 net/bpf/test_run.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index cbd4fb65aa4f..2221573dacdb 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -347,6 +347,9 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const 
union bpf_attr *kattr,
        void *data;
        int ret;
 
+       if (kattr->test.ctx_in || kattr->test.ctx_out)
+               return -EINVAL;
+
        data = bpf_test_init(kattr, size, XDP_PACKET_HEADROOM + NET_IP_ALIGN, 
0);
        if (IS_ERR(data))
                return PTR_ERR(data);
@@ -390,6 +393,9 @@ int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog,
        if (prog->type != BPF_PROG_TYPE_FLOW_DISSECTOR)
                return -EINVAL;
 
+       if (kattr->test.ctx_in || kattr->test.ctx_out)
+               return -EINVAL;
+
        data = bpf_test_init(kattr, size, NET_SKB_PAD + NET_IP_ALIGN,
                             SKB_DATA_ALIGN(sizeof(struct skb_shared_info)));
        if (IS_ERR(data))
-- 
2.21.0.392.gf8f6787159e-goog