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Subject: 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 <johannes@sipsolutions.net>
To:     Aleksandr Nogikh <a.nogikh@gmail.com>, davem@davemloft.net,
        kuba@kernel.org, akpm@linux-foundation.org
Cc:     edumazet@google.com, andreyknvl@google.com, dvyukov@google.com,
        elver@google.com, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
        nogikh@google.com
Date:   Sun, 11 Oct 2020 20:50:00 +0200
In-Reply-To: <20201009170202.103512-1-a.nogikh@gmail.com> (sfid-20201009_190209_250951_9651A9CD)
References: <20201009170202.103512-1-a.nogikh@gmail.com>
         (sfid-20201009_190209_250951_9651A9CD)
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On Fri, 2020-10-09 at 17:01 +0000, Aleksandr Nogikh wrote:
> From: Aleksandr Nogikh <nogikh@google.com>
> 
> 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