Skip to content

Commit

Permalink
bpf: mark bpf_dummy_struct_ops.test_1 parameter as nullable
Browse files Browse the repository at this point in the history
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 <[email protected]>
Signed-off-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
  • Loading branch information
eddyz87 authored and Alexei Starovoitov committed Apr 25, 2024
1 parent 638a485 commit 1479eaf
Showing 1 changed file with 2 additions and 2 deletions.
4 changes: 2 additions & 2 deletions net/bpf/bpf_dummy_struct_ops.c
Original file line number Diff line number Diff line change
Expand Up @@ -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;
}
Expand All @@ -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,
};
Expand Down

0 comments on commit 1479eaf

Please sign in to comment.