Return-path: Received: from mail-lb0-f178.google.com ([209.85.217.178]:33241 "EHLO mail-lb0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751574AbbETTUE (ORCPT ); Wed, 20 May 2015 15:20:04 -0400 Received: by lbbzk7 with SMTP id zk7so2005406lbb.0 for ; Wed, 20 May 2015 12:20:02 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <555CB8C1.1040007@lwfinger.net> References: <1432014444-29039-1-git-send-email-haggai.eran@gmail.com> <555CB8C1.1040007@lwfinger.net> Date: Wed, 20 May 2015 22:20:02 +0300 Message-ID: (sfid-20150520_212009_515676_93DFCE74) Subject: Re: [PATCH] staging: rtl8712: prevent buffer overrun in recvbuf2recvframe From: Haggai Eran To: Larry Finger Cc: linux-wireless@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 20 May 2015 at 19:39, Larry Finger wrote: > On 05/20/2015 01:17 AM, Haggai Eran wrote: >> >> On May 19, 2015 08:47, "Haggai Eran" > > wrote: >> > >> > With an RTL8191SU USB adaptor, sometimes the hints for a fragmented >> > packet are set, but the packet length is too large. Truncate the packet >> > to prevent memory corruption. >> > >> > Signed-off-by: Haggai Eran > > >> > --- >> > >> > Hi, >> > >> > I think this solves the issue for me. I'll test it more thoroughly >> later. I >> > still don't know why a fragmented packet has such a large pkt_len value >> though. >> > >> > Thanks, >> > Haggai >> > >> >> I guess I was too quick with this patch. It prevents the kernel page >> faults, but >> with it I still see sometimes the connectivity disappear for a minute or >> two. > > > Is anything logged when that happens? No. I get once in a while the other corrupted entries I told you about, but nothing special to these freezes > I'm still trying to see where that magic number of 1658 comes from, and how > that affects the RX buffer size. I tried to look at the new driver (rtl8192su), but it doesn't seem to handle this more-fragment bit at all. > When I unconditionally set alloc_sz to tmp_len as in the attached patch (I > remembered to refresh it this time), nothing bad has happened here yet. What > happens on your box? The same freezes still occur. Thanks, Haggai