skb_over_panic using UDP and 6lowpan / fakelb

From: David Palma
Date: Mon Mar 27 2017 - 05:25:08 EST



Hi,

Sending a simple UDP packet (39 bytes long), over a 6lowpan interface
(using fakelb), creates a kernel panic (skb_over_panic).

Steps to reproduce, and more details, can be found in:
https://github.com/PalmaITEM/6lowpan-skb_over_panic

This bug has been reported in
https://bugzilla.kernel.org/show_bug.cgi?id=195059

I have found that lengths around 39 bytes can also trigger this
behaviour and that longer packets are handled without problem.

Verified in:

- Linux version 4.9.0-0.bpo.2-amd64 (debian-kernel@xxxxxxxxxxxxxxxx)
(gcc version 4.9.2 (Debian 4.9.2-10) ) #1 SMP Debian 4.9.13-1~bpo8+1
(2017-02-27)
- Linux version 4.10.4-1-ARCH (builduser@tobias) (gcc version 6.3.1
20170306 (GCC) ) #1 SMP PREEMPT Sat Mar 18 19:39:18 CET 2017


I am not familiar with the process of reporting kernel bugs, so
apologies beforehand. I am also available to provide any missing
information.

Cheers,
--
David Palma

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