From: Eric Dumazet <eduma...@google.com>
Date: Tue, 2 Oct 2018 15:47:35 -0700
> We have an impressive number of syzkaller bugs that are linked
> to the fact that syzbot was able to create a networking device
> with millions of TX (or RX) queues.
>
> Let's limit the number of RX/TX queues to 4096, this really should
> cover all known cases.
>
> A separate patch will add various cond_resched() in the loops
> handling sysfs entries at device creation and dismantle.
>
> Tested:
>
> lpaa6:~# ip link add gre-4097 numtxqueues 4097 numrxqueues 4097 type ip6gretap
> RTNETLINK answers: Invalid argument
>
> lpaa6:~# time ip link add gre-4096 numtxqueues 4096 numrxqueues 4096 type
> ip6gretap
>
> real 0m0.180s
> user 0m0.000s
> sys 0m0.107s
>
> Fixes: 76ff5cc91935 ("rtnl: allow to specify number of rx and tx queues on
> device creation")
> Signed-off-by: Eric Dumazet <eduma...@google.com>
> Reported-by: syzbot <syzkal...@googlegroups.com>
Applied and queued up for -stable.
