On Thu, Feb 16, 2017 at 10:52:19AM -0500, Soheil Hassas Yeganeh wrote: > On Thu, Feb 16, 2017 at 10:50 AM, Soheil Hassas Yeganeh > <soh...@google.com> wrote: > > Thank you Vito for the report. > > > > The patch you cited actually resolves a similar backward compatibility > > problem for traceroute. > > > > I suspect the problem here is that there's a local error queued on the > > error queue after an ICMP message. ping apparently expect the > > sk->sk_err to be set for the local errors as well, and hence the > > error. Ideally, ping should read the error queue if there an EPOLLERR, > > because local errors never sk->sk_err on their own. That is, if we > > have > > [oops] That is, if we have only one local error on the error queue, we > cannot rely on having an error on recvmsg (i.e., sk->sk_err being set) > even in 4.9. > > <snip>
Hi Soheil, This doesn't appear to be trivially reproducible here by just running ping as it were originally discovered. I'll see if I can reliably cause the malfunction somehow, but until then I can't meaningfully test patches. Perhaps a form of fault injection would make more sense if there's a reasonable idea of what this is stemming from? I've opened an issue with iputils on github in the event that this is found to be a ping bug. Your input might be helpful there as well: https://github.com/iputils/iputils/issues/74 Thanks, Vito Caputo
