Hi, Enclosed are a pair of patches for an oops that can occur if an exception is generated while a bpf subprogram is running. One of the bpf_prog_aux entries for the subprograms are missing an extable. This can lead to an exception that would otherwise be handled turning into a NULL pointer bug.
The bulk of the change here is simply adding a pair of programs for the selftest. The proposed fix in this iteration is a 1-line change.
These changes were tested via the verifier and progs selftests and no regressions were observed.
Changes from v1:
- Add a selftest (Feedback From Alexei Starovoitov) - Move to a 1-line verifier change instead of searching multiple extables
Krister Johansen (2): Add a selftest for subprogram extables bpf: ensure main program has an extable
kernel/bpf/verifier.c | 1 + .../bpf/prog_tests/subprogs_extable.c | 35 +++++++++ .../bpf/progs/test_subprogs_extable.c | 71 +++++++++++++++++++ 3 files changed, 107 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/subprogs_extable.c create mode 100644 tools/testing/selftests/bpf/progs/test_subprogs_extable.c