From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: net: kernel BUG() in net/netns/generic.h:45 Date: Thu, 05 Apr 2012 18:20:46 -0400 Message-ID: <1333664446.3538.12.camel@lappy> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Dave Jones , linux-kernel , netdev To: davem , Eric Dumazet , Eric Van Hensbergen , ebiederm Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi all, When an initialization of a network namespace in setup_net() fails, we try to undo everything by executing each of the exit callbacks of every namespace in the network. The problem is, it might be possible that the net_generic array wasn't initialized before we fail and try to undo everything. At that point, some of the networks assume that since we're already calling the exit callback, the net_generic structure is initialized and we hit the BUG() in net/netns/generic.h:45 . I'm not quite sure whether the right fix from the following three options is, and would be happy to figure it out before fixing it: 1. Don't assume net_generic was initialized in the exit callback, which is a bit problematic since we can't query that nicely anyway (a sub-option here would be adding an API to query whether the net_generic structure is initialized. 2. Remove the BUG(), switch it to a WARN() and let each subsystem handle the case of NULL on it's own. While it sounds a bit wrong, it's worth mentioning that that BUG() was initially added in an attempt to fix an issue in CAIF, which was fixed in a completely different way afterwards, so it's not strictly necessary here. 3. Only call the exit callback for subsystems we have called the init callback for. Thanks! -- Sasha.