Random ringbuf reader creation failures: add fd to epoll: bad file descriptor

[pawelbeza]

Describe the bug

Hey we're getting randomly errors like this add fd to epoll: bad file descriptor when creating ringbuf reader with NewReader().

Any guidance what we could look into. I'd love to contribute fix or improve error messaging:)

How to reproduce

That's tough as it pops up quite randomly:/

I think that might happen when underlying ebpf program got ungracefully detached (for example we attach ebpf to network interface -> interface gets deleted -> we fail to create new reader). But I'm really not sure as error message is not clear.

Version information

github.com/cilium/ebpf v0.16.1

[florianl]

Hey @pawelbeza 👋

Could you try to narrow down the issue a bit more? The ring buffer and eBPF program should be loaded before it gets attached to a network interface. Deleting a network interface should therefore not have an effect on the ring buffer.

Could you provide a minimal reproducer that shows how you use the ring buffer?