Re: [PATH v2] scsi: scsi_dh_rdac: Avoid crash during rdac_bus_attach

[Bart Van Assche]

On 7/28/21 7:24 AM, yebin wrote:
> On 2021/7/23 12:04, Bart Van Assche wrote:
> > On 1/12/21 10:31 PM, Ye Bin wrote:
> > >       sdev->handler_data = NULL;
> > > +    synchronize_rcu();
> > >       kfree(h);
> > What is the purpose of the new synchronize_rcu() call?
> Thanks for your reply.
> Yes, I add new synchronize_rcu() call is to wait until *h is no longer 
> in use. If free
> "h" right now , mybe lead to UAF.
> > If its purpose is
> > to wait until *h is no longer in use, please use kfree_rcu() instead.
> struct rdac_dh_data {
>          struct list_head        node;
>          .....
> }
> As rdac_dh_data.node type is "struct list_head", but  kfree_rcu the 
> first parameter type is
> "struct rcu_head". So we can only use synchronize_rcu() at here.

Ah, that's right. Hence:

Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>