netdev - Re: [PATCH] Fix up truesize after pskb_expand

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 05 Jan 2009 14:31:15 +0100
From:	Johannes Berg <johannes@...solutions.net>
To:	Andi Kleen <andi@...stfloor.org>
Cc:	linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
	linville@...driver.com, davem <davem@...emloft.net>
Subject: Re: [PATCH] Fix up truesize after pskb_expand_head() in wireless
	stack

On Mon, 2009-01-05 at 14:36 +0100, Andi Kleen wrote:
> On Mon, Jan 05, 2009 at 02:16:19PM +0100, Johannes Berg wrote:
> > > I didn't use any monitoring with this. No tcpdump, no wireless
> > > sniffer tools or anything. It happened all the time during
> > > normal operation.
> > 
> > You did have a monitor interface up though, didn't you? If nothing
> 
> wmaster0 was up. Is that a monitoring interface? 

No. Only if you do iwconfig ... mode monitor or use iw to create one or
something like that.

I was under the impression that you only modified monitor mode code, but
upon closer inspection (really, you should diff with -p, makes it a lot
easier to review) it seems that you also touched packet defragmentation
code. Are you running a low fragmentation threshold on your network?

Can you
check /sys/kernel/debug/ieee80211/phy*/statistics/rx_expand_skb_head*
please?

> > actually used those skbs then it's likely that the warning didn't result
> > in any corruption at all.
> 
> Nothing was corrupted ever to my knowledge, just lots of spam in my kernel logs.

You wouldn't easily notice any socket memory charge corruption anyway.

johannes

Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)