From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: r8169: instant crash if receiving packet larger than MTU Date: Sat, 14 Feb 2009 18:16:36 +0300 Message-ID: <4996E054.20905@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev Return-path: Received: from isrv.corpit.ru ([81.13.33.159]:46920 "EHLO isrv.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750752AbZBNPQq (ORCPT ); Sat, 14 Feb 2009 10:16:46 -0500 Sender: netdev-owner@vger.kernel.org List-ID: I played with jumbo frames today at home on two machines with built-in r8169 NICs. And discovered that, after enabling larger packets on one machine, it's sufficient to send SINGLE packet to immediately, instantly crash the other machine. I'd say it's quite a serious issue. Good it usually can't be triggered "from outside" (from the Internet) because there, standard 1500-sized MTU is usually used (or at least in last-mile network segment), but on LAN it's quite common nowadays to at least HAVE the jumbo-capable equipment, and that's all what's needed to trigger this. Comments? (The system in question is based on an Asus M3A78-EM motherboard, here's the lspci info for the NIC: 02:00.0 0200: 10ec:8168 (rev 02) Subsystem: 1043:82c6 Flags: bus master, fast devsel, latency 0, IRQ 509 I/O ports at e800 [size=256] Memory at fbeff000 (64-bit, non-prefetchable) [size=4K] Memory at faff0000 (64-bit, prefetchable) [size=64K] Expansion ROM at fbec0000 [disabled] [size=128K] Capabilities: [40] Power Management version 3 Capabilities: [50] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable+ Capabilities: [70] Express Endpoint, MSI 01 Capabilities: [b0] MSI-X: Enable- Mask- TabSize=2 Capabilities: [d0] Vital Product Data Capabilities: [100] Advanced Error Reporting Capabilities: [140] Virtual Channel Capabilities: [160] Device Serial Number 81-68-10-ec-00-00-00-00 Kernel driver in use: r8169 Kernel modules: r8169 ) Thanks! /mjt