qnetworkinterface_linux.cpp hits assert isDump == !!(hdr->nlmsg_flags & NLM_F_MULTI)

I randomly hit this assert:
ASSERT: "isDump == !!(hdr->nlmsg_flags & NLM_F_MULTI)" in file /d/qt/5/kde/qtbase/src/network/kernel/qnetworkinterface_linux.cpp, line 182

(in apps that are not related to network at all, like zanshin, and at that time I wasn't doing anything related to networking on the machine)

hdr->nlmsg_flags is 0 at that point.
Obviously it wasn't 0 in the first message, but well, this code loops around and reads other messages, so that assert seems to rely on consistency between messages?

Let me know if there's anything I can do to provide more information; I'll try adding debug output but I fear it'll be noisy...