netdev - Re: [PATCH] mac80211: Fix TX after monitor interface is converted to managed

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 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:	Thu, 4 Oct 2007 08:54:40 -0700
From:	Stephen Hemminger <shemminger@...ux-foundation.org>
To:	Daniel Drake <dsd@...too.org>
Cc:	linville@...driver.com, johannes@...solutions.net,
	netdev@...r.kernel.org, linux-wireless@...r.kernel.org
Subject: Re: [PATCH] mac80211: Fix TX after monitor interface is converted
 to managed

On Thu,  4 Oct 2007 12:33:43 +0100 (BST)
Daniel Drake <dsd@...too.org> wrote:

> This sequence of events causes loss of connectivity:
> 
> <plug in>
> <associate as normal in managed mode>
> ifconfig eth7 down
> iwconfig eth7 mode monitor
> ifconfig eth7 up
> ifconfig eth7 down
> iwconfig eth7 mode managed
> <associate as normal>
> 
> At this point you are associated but TX does not work. This is because
> the eth7 hard_start_xmit is still ieee80211_monitor_start_xmit.
> 
> Fix this by unsetting the hard_start_xmit handler in ieee80211_if_reinit. It
> will then be reinitialised to the default (ieee80211_subif_start_xmit) in
> ieee80211_if_set_type.
> 
> Signed-off-by: Daniel Drake <dsd@...too.org>

Playing with the function pointer is a awkward way to do this.  Shouldn't
the state management flags be used instead (dormant, running, stop/wake)...
I am concerned about races and dereferencing the NULL ptr.

-- 
Stephen Hemminger <shemminger@...ux-foundation.org>
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html