Crash with BCM4312 using ad-hoc mode and promiscuous

[Larry Finger <Larry.Finger@lwfinger.net>]

On 07/20/2010 03:18 PM, Harry Bullen wrote:
> Hey, I've been using a Broadcom BCM4312 on Ubuntu 10.04 kernel
> 2.6.32-23.  I found a way to crash the machine and wanted to know if
> it was a known problem and if so is there a solution.  If not I'd like
> to report this as a bug.
> I first join an existing ad-hoc network and and assign myself an ipv4
> address.  Then I use tcpdump or wireshark to listen to traffic in
> promiscuous mode.  Finally I generate I traffic between two other
> computers on the same ad-hoc network by having one ping the other.  At
> this point the system freezes up immediately (including ssh sessions
> and it cannot be pinged) and I have to hold down the power button to
> reboot it.  If I use an AP, don't put the card in promiscuous mode
> (when using tcpdump or wireshark) or don't generate traffic between
> other computers the system doesn't crash.

Is this a crash or a freeze? A crash would provide a crash dump, but a freeze 
does not and they are harder to debug. With a KDE desktop, it is possible to 
switch to a logging console to capture whatever info is available. Is this 
possible with Gnome? Are you using a standard kernel or one you built yourself? 
If the former, could you please provide the configuration? It should be found in 
/proc/config.gz. If you are compiling yourself, then select 
CONFIG_DETECT_SOFTLOCKUP and CONFIG_DETECT_HUNG_TASK in the Kernel Hacking section.

> Other issues that may or may not be related.  The wireless card
> sometimes switches between eth1 and eth2 after a reboot (I haven't
> seen a pattern in this.)  When sniffing traffic on a wireless network
> using an AP I only see traffic that is broadcast or sent to me,
> even-though I am in promiscuous mode.

The naming should be controlled by udev according to the rules in 
/etc/udev/rules.d/70-persistent-network.rule. At least it works that way on my 
system.

> I have installed b43-fwcutter via: apt-get install b43-fwcutter.  But
> this did not appear to have any effect.

As that package only installs the program that extracts firmware from a Broadcom 
driver, there is no reason to expect it to make a difference.

I will try to duplicate your result.

Larry