AZL-54072

In the Linux kernel, the following vulnerability has been resolved:

bpf: mark bpfdummystructops.test1 parameter as nullable

Test case dummystops/dummyinitretvalue passes NULL as the first parameter of the test1() function. Mark this parameter as nullable to make verifier aware of such possibility. Otherwise, NULL check in the test_1() code:

  SEC("struct_ops/test_1")
  int BPF_PROG(test_1, struct bpf_dummy_ops_state *state)
  {
        if (!state)
                return ...;

        ... access state ...
  }

Might be removed by verifier, thus triggering NULL pointer dereference under certain conditions.