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bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable

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Test case dummy_st_ops/dummy_init_ret_value passes NULL as the first
parameter of the test_1() 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.

Reported-by: Jose E. Marchesi <jemarch@gnu.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20240424012821.595216-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Eduard Zingerman 2024-04-23 18:28:17 -07:00 committed by Alexei Starovoitov
parent 638a485c49
commit 1479eaff1f
1 changed files with 2 additions and 2 deletions
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4
net/bpf/bpf_dummy_struct_ops.c
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@ -232,7 +232,7 @@ static void bpf_dummy_unreg(void *kdata)
{
}
static int bpf_dummy_test_1(struct bpf_dummy_ops_state *cb)
static int bpf_dummy_ops__test_1(struct bpf_dummy_ops_state *cb__nullable)
{
return 0;
}
@ -249,7 +249,7 @@ static int bpf_dummy_test_sleepable(struct bpf_dummy_ops_state *cb)
}
static struct bpf_dummy_ops __bpf_bpf_dummy_ops = {
.test_1 = bpf_dummy_test_1,
.test_1 = bpf_dummy_ops__test_1,
.test_2 = bpf_dummy_test_2,
.test_sleepable = bpf_dummy_test_sleepable,
};