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Patch 1 adds the missing type_may_be_null() guard. Patch 2 adds a selftest with a test runner. Changes in v4: - Add test runner in prog_tests/ so the test is actually invoked by test_progs (Kumar) Changes in v3: - Drop stack trace from commit log - Split kernel fix and selftest into separate patches - Use [PATCH bpf] prefix Changes in v2: - Add selftest Link: https://lore.kernel.org/bpf/20260402092923.38357-1-tpluszz77@gmail.com/ (v3) Link: https://lore.kernel.org/all/20260401142316.2452-1-tpluszz77@gmail.com/ (v2) Link: https://lore.kernel.org/all/20260331172720.29938-1-tpluszz77@gmail.com/ (v1) Qi Tang (2): bpf: reject direct access to nullable PTR_TO_BUF pointers selftests/bpf: add test for nullable PTR_TO_BUF access kernel/bpf/verifier.c | 3 ++- tools/testing/selftests/bpf/prog_tests/iter_buf_null_fail.c | 9 +++++++++ tools/testing/selftests/bpf/progs/iter_buf_null_fail.c | 51 ++++++++++++ 3 files changed, 62 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/iter_buf_null_fail.c create mode 100644 tools/testing/selftests/bpf/progs/iter_buf_null_fail.c