[PATCHv3 net 0/2] net: fixes for device unregistration

[Julian Anastasov <ja@ssi.bg>]

Test script from Eric W. Biederman can catch a problem
where packets from backlog are processed long after the last
synchronize_net call. This can be reproduced after few tests
if commit 381c759d9916 ("ipv4: Avoid crashing in ip_error")
is reverted for the test. Incoming packets do not hold
reference to device but even if they do, subsystems do not
expect packets to fly during and after the NETDEV_UNREGISTER
event.

The first fix has the cost of netif_running check in fast path.
The second fix calls rcu_read_lock while local IRQ is disabled,
I hope this is not against the rules.

Julian Anastasov (2):
  net: do not process device backlog during unregistration
  net: call rcu_read_lock early in process_backlog

 net/core/dev.c | 38 ++++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

-- 
1.9.3