bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Check rcu_read_lock_trace_held() in bpf_map_lookup_percpu_elem() bpf_map_lookup_percpu_elem() helper is also available for sleepable bpf program. When BPF JIT is disabled or under 32-bit host, bpf_map_lookup_percpu_elem() will not be inlined. Using it in a sleepable bpf program will trigger the warning in bpf_map_lookup_percpu_elem(), because the bpf program only holds rcu_read_lock_trace lock. Therefore, add the missed check.

References

• https://git.kernel.org/stable/c/2f8c69a72e8ad87b36b8052f789da3cc2b2e186c
• https://git.kernel.org/stable/c/7bf4461f1c97207fda757014690d55a447ce859f
• https://git.kernel.org/stable/c/2d834477bbc1e8b8a59ff8b0c081529d6bed7b22
• https://git.kernel.org/stable/c/b522d4d334f206284b1a44b0b0b2f99fd443b39b
• https://git.kernel.org/stable/c/d4965578267e2e81f67c86e2608481e77e9c8569