[PATCH bpf-next 0/2] bpf: Track overlapping RCU protection

[Ning Ding <dingning04@gmail.com>]

Preemption-disabled and IRQ-disabled regions provide RCU protection, but
the verifier does not account for them. Current implementation can invalidate 
a task kptr while another RCU source remains active, or keep it valid 
after the final source ends.

Track these regions and invalidate RCU-protected pointers only after the
last protection ends. Add task kptr tests for overlapping protection and
final-exit rejection.

This follows review of the applied spin-unlock fix series [1].

Tested in QEMU/KVM:
  ./test_progs -t task_kfunc
  ./test_progs -t preempt_lock
  ./test_progs -t irq

[1] https://lore.kernel.org/r/20260803112615.3362122-1-dingning04@gmail.com

Ning Ding (2):
  bpf: Account for preempt and IRQ state in RCU protection
  selftests/bpf: Test overlapping RCU protection

 kernel/bpf/verifier.c                         |  13 +-
 .../selftests/bpf/prog_tests/task_kfunc.c     |   6 +
 .../selftests/bpf/progs/task_kfunc_common.h   |   2 +
 .../selftests/bpf/progs/task_kfunc_failure.c  |  49 ++++++
 .../selftests/bpf/progs/task_kfunc_success.c  | 147 ++++++++++++++++++
 5 files changed, 214 insertions(+), 3 deletions(-)


base-commit: 11c1e836710dcba03e50454a4eedfdbaf8d3050e
-- 
2.43.0