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| author | Julian Anastasov <ja@ssi.bg> | 2015-07-09 08:59:10 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-07-11 03:16:36 +0200 |
| commit | 2c17d27c36dcce2b6bf689f41a46b9e909877c21 (patch) | |
| tree | 8868fe137839c66fcef2a435d8d1b38fd0cd7533 /lib/kobject.c | |
| parent | net: do not process device backlog during unregistration (diff) | |
| download | linux-2c17d27c36dcce2b6bf689f41a46b9e909877c21.tar.xz linux-2c17d27c36dcce2b6bf689f41a46b9e909877c21.zip | |
net: call rcu_read_lock early in process_backlog
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>
Diffstat (limited to 'lib/kobject.c')
0 files changed, 0 insertions, 0 deletions