diff options
| author | Julian Anastasov <ja@ssi.bg> | 2015-07-09 09:59:10 +0300 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2016-08-26 20:02:22 +0200 |
| commit | 064af0c2f86309e73b98f7bc4dae2f8ea9706756 (patch) | |
| tree | 4489350ed447893bab6cb4b824b326763811d953 /scripts | |
| parent | a454d9740fe378b4a27520d575d6ec0105ace8e8 (diff) | |
net: call rcu_read_lock early in process_backlog
[ Upstream commit 2c17d27c36dcce2b6bf689f41a46b9e909877c21 ]
Incoming packet should be either in backlog queue or
in RCU read-side section. Otherwise, the final sequence of
flush_backlog() and synchronize_net() may miss packets
that can run without device reference:
CPU 1 CPU 2
skb->dev: no reference
process_backlog:__skb_dequeue
process_backlog:local_irq_enable
on_each_cpu for
flush_backlog => IPI(hardirq): flush_backlog
- packet not found in backlog
CPU delayed ...
synchronize_net
- no ongoing RCU
read-side sections
netdev_run_todo,
rcu_barrier: no
ongoing callbacks
__netif_receive_skb_core:rcu_read_lock
- too late
free dev
process packet for freed dev
Fixes: 6e583ce5242f ("net: eliminate refcounting in backlog queue")
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Guendhoer <stefan@guendhoer.com>
Diffstat (limited to 'scripts')
0 files changed, 0 insertions, 0 deletions