On Tue, 30 Oct 2007 15:38:30 -0700 (PDT) David Miller <[EMAIL PROTECTED]> wrote:
> From: Daniel Lezcano <[EMAIL PROTECTED]> > Date: Tue, 30 Oct 2007 17:19:26 +0100 > > > Point 1: > > The unregistering of a network device schedule a netdev_run_todo. > > This function calls dev->destructor when it is set and the > > destructor calls free_netdev. > > > > Point 2: > > In the case of an initialization of a network device the usual code > > is: > > * alloc_netdev > > * register_netdev > > -> if this one fails, call free_netdev and exit with error. > > > > Point 3: > > In the register_netdevice function at the later state, when the device > > is at the registered state, a call to the netdevice_notifiers is made. > > If one of the notification falls into an error, a rollback to the > > registered state is done using unregister_netdevice. > > > > Conclusion: > > When a network device fails to register during initialization because > > one network subsystem returned an error during a notification call > > chain, the network device is freed twice because of fact 1 and fact 2. > > The second free_netdev will be done with an invalid pointer. > > > > Proposed solution: > > The following patch move all the code of unregister_netdevice *except* > > the call to net_set_todo, to a new function "rollback_registered". > > > > The following functions are changed in this way: > > * register_netdevice: calls rollback_registered when a notification fails > > * unregister_netdevice: calls rollback_register + net_set_todo, the call > > order to net_set_todo is changed because it is the > > latest now. Since it justs add an element to a list > > that should not break anything. > > > > Signed-off-by: Daniel Lezcano <[EMAIL PROTECTED]> > > Looks good, applied. Agreed, but I wish the unwind code wouldn't have to be separate function. -- Stephen Hemminger <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
