On Fri, 2017-08-18 at 15:58 -0700, David Miller wrote: > From: Eric Dumazet <eric.duma...@gmail.com> > Date: Fri, 18 Aug 2017 06:13:49 -0700 > > > On Thu, 2017-08-17 at 22:21 -0700, David Miller wrote: > >> From: Eric Dumazet <eric.duma...@gmail.com> > >> Date: Thu, 17 Aug 2017 15:30:40 -0700 > >> > >> > So we do not really know if we need to clean up or not. > >> > >> We always know, the answer is that whenever register_netdev() fails we > >> never need to perform any cleanup which is done by priv_destructor. > >> > >> > Any idea how to fix the issue ? > >> > >> Your patch is exactly how we should fix this, but without the comment. > >> The logic is straightforward. > >> > >> If register_netdevice() fails any resources handled by priv_destructor > >> are cleaned up, it is guaranteed. > > > > Not in current code. > > > > There are some failures which do a "goto out;" > > > > out: > > return ret; > > > > > > In these cases, priv_destructor is not called. > > > > So we need multiple fixes I think :/ > > I don't think so. > > The cases that "goto out;" in register_netdevce() are those that > execute before ->ndo_init() succeeds. > > Only if ->ndo_succeeds() runs successfully should ->priv_destructor() > need execute. > > So everything is fine as far as I can see.
Let look at tun->pcpu_stats, for example. It is allocated at line 1831, before the register_netdevice() drivers/net/tun.c does not provide ndo_init()
