Re: [PATCH v2 0/3] [PATCH v2 0/3] [PATCH v2 0/3] net, mac80211, kernel: enable KCOV remote coverage collection for 802.11 frame handling

From: Johannes Berg
Date: Sun Oct 11 2020 - 14:50:22 EST


On Fri, 2020-10-09 at 17:01 +0000, Aleksandr Nogikh wrote:
> From: Aleksandr Nogikh <nogikh@xxxxxxxxxx>
>
> This patch series enables remote KCOV coverage collection during
> 802.11 frames processing. These changes make it possible to perform
> coverage-guided fuzzing in search of remotely triggerable bugs.

Btw, it occurred to me that I don't know at all - is this related to
syzkaller? Or is there some other fuzzing you're working on? Can we get
the bug reports from it if it's different? :)


Also, unrelated to that (but I see Dmitry CC'ed), I started wondering if
it'd be helpful to have an easier raw 802.11 inject path on top of say
hwsim0; I noticed some syzbot reports where it created raw sockets, but
that only gets you into the *data* plane of the wifi stack, not into the
*management* plane. Theoretically you could add a monitor interface, but
right now the wifi setup (according to the current docs on github) is
using two IBSS interfaces.

Perhaps an inject path on the mac80211-hwsim "hwsim0" interface would be
something to consider? Or simply adding a third radio that's in
"monitor" mode, so that a raw socket bound to *that* interface can
inject with a radiotap header followed by an 802.11 frame, getting to
arbitrary frame handling code, not just data frames.

Any thoughts?

johannes