Re: [PATCH] mac80211_hwsim: correctly handle zero length frames

From: Johannes Berg
Date: Fri Jun 18 2021 - 05:36:37 EST


On Thu, 2021-06-10 at 21:49 +0530, Anirudh Rayabharam wrote:
> syzbot, using KMSAN, has reported an uninit-value access in
> hwsim_cloned_frame_received_nl(). This is happening because frame_data_len
> is 0. The code doesn't detect this case and blindly tries to read the
> frame's header.
>
> Fix this by bailing out in case frame_data_len is 0.

This really seems quite pointless - you should bail out if the frame is
too short for what we need to do, not just when it's 0.

johannes