Hi, As far as I understand pskb_may_pull() plays important role in packet parsing for all protocols. And we did custom fragmentation of packets emitted via tun (IFF_NAPI_FRAGS). However, it seems that it does not give any results (bugs found), and I think the reason for this is that linear data is rounded up and is usually quite large. So if a parsing function does pskb_may_pull(1), or does not do it at all, it can usually access more and it will go unnoticed. KASAN has an ability to do custom poisoning: it can poison/unpoison any memory range, and then detect any reads/writes to that range. What do you think about adding custom KASAN poisoning to pskb_may_pull() and switching it to non-eager mode (pull only what was requested) under KASAN? Do you think it has potential for finding important bugs? What amount of work is this?
Thanks
