On Sat, Mar 18, 2017 at 08:49:43PM -0700, Cong Wang wrote: > On Sat, Mar 18, 2017 at 6:48 PM, Kevin Xu <kaiwen...@hulu.com> wrote: > > In some rare cases, inet_sk_rx_dst_set() may be called multiple times > > on the same dst, causing double refcounting. Eventually, it > > prevents net_device to be destroyed. The bug manifested as > > > > unregister_netdevice: waiting for lo to become free. Usage count = 1 > > > > in the kernel log, preventing new network namespace creation. > > > > Signed-off-by: Kevin Xu <kaiwen...@hulu.com> > > Don't know why you don't follow the discussion on your v1... > > It is protected by bh_lock_sock(), so your patch is not needed > at all. > > Read net/ipv4/udp.c: > > 1762 /* For TCP sockets, sk_rx_dst is protected by socket lock > 1763 * For UDP, we use xchg() to guard against concurrent changes. > 1764 */
I probably misunderstood. Do you mean v2 patch is actually not needed or the whole workaround is not necessary?
