On Mon, Jan 15, 2018 at 3:15 PM, Dmitry Vyukov <dvyu...@google.com> wrote: > 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?
Filed https://bugzilla.kernel.org/show_bug.cgi?id=199055 for this so it's not get lost.