[PATCH v1 0/3] Fix use-after-free race in bpf_prog_info synthesis

[Ian Rogers <irogers@google.com>]

The addition of more use of bpf_prog_info for gather BPF metadata in:
https://lore.kernel.org/all/20250612194939.162730-1-blakejones@google.com/
and the ever richer perf trace testing, such as:
https://lore.kernel.org/all/20250528191148.89118-1-howardchu95@gmail.com/
frequently triggered a latent perf bug in v6.17 when the perf and
libbpf updates came together. The bug would cause segvs and was reported here:
https://lore.kernel.org/lkml/CAP-5=fWJQcmUOP7MuCA2ihKnDAHUCOBLkQFEkQES-1ZZTrgf8Q@mail.gmail.com/

To fix the issue the 1st and 3rd patch are necessary. Both patches
address a race of either the sideband thread updating perf's state or
the kernel state changing over two system calls.

The use-after-free was introduced by:
https://lore.kernel.org/r/20241205084500.823660-4-quic_zhonhan@quicinc.com
The lack of failing getting the bpf_prog_info for changes in the
kernel was introduced in:
https://lore.kernel.org/r/20211011082031.4148337-4-davemarchevsky@fb.com

As v6.17 is currently actively segv-ing in perf test I'd recommend
these patches go into v6.17 asap.

When running the perf tests on v6.17 I frequently see less critical
test failures addressed in:
https://lore.kernel.org/all/20250821221834.1312002-1-irogers@google.com/

Ian Rogers (3):
  perf bpf-event: Fix use-after-free in synthesis
  perf bpf-utils: Constify bpil_array_desc
  perf bpf-utils: Harden get_bpf_prog_info_linear

 tools/perf/util/bpf-event.c | 39 ++++++++++++++++--------
 tools/perf/util/bpf-utils.c | 61 ++++++++++++++++++++++++-------------
 2 files changed, 66 insertions(+), 34 deletions(-)

-- 
2.51.0.355.g5224444f11-goog