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alistair23-linux/net/core
Julian Anastasov 2c17d27c36 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: 6e583ce524 ("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>
2015-07-10 18:16:36 -07:00
..
Makefile net: bury net/core/iovec.c - nothing in there is used anymore 2015-02-04 01:34:15 -05:00
datagram.c new helper: msg_data_left() 2015-04-11 15:53:35 -04:00
dev.c net: call rcu_read_lock early in process_backlog 2015-07-10 18:16:36 -07:00
dev_addr_lists.c net: fix spelling for synchronized 2014-11-18 15:26:32 -05:00
dev_ioctl.c dev_ioctl: use sizeof(x) instead of sizeof x 2014-11-18 15:27:32 -05:00
drop_monitor.c net: Replace get_cpu_var through this_cpu_ptr 2014-08-26 13:45:47 -04:00
dst.c dst: no need to take reference on DST_NOCACHE dsts 2014-12-09 16:08:17 -05:00
ethtool.c net/ethtool: Add current supported tunable options 2015-06-11 00:36:37 -07:00
fib_rules.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-06 22:34:15 -04:00
filter.c bpf: disallow bpf tc programs access current->pid,uid 2015-06-15 20:51:20 -07:00
flow.c flowcache: Fix kernel panic in flow_cache_flush_task 2015-02-05 14:38:53 -08:00
flow_dissector.c flow_dissector: Pre-initialize ip_proto in __skb_flow_dissect() 2015-06-28 16:53:54 -07:00
gen_estimator.c net_sched: gen_estimator: extend pps limit 2015-07-08 13:59:20 -07:00
gen_stats.c gen_stats.c: Duplicate xstats buffer for later use 2015-02-19 15:45:53 -05:00
link_watch.c dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
neighbour.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
net-procfs.c rps: selective flow shedding during softnet overflow 2013-05-20 13:48:04 -07:00
net-sysfs.c switchdev: don't use anonymous union on switchdev attr/obj structs 2015-05-13 14:20:59 -04:00
net-sysfs.h net: netdev_kobject_init: annotate with __init 2014-01-05 20:27:54 -05:00
net-traces.c net: Add export.h for EXPORT_SYMBOL/THIS_MODULE to non-modules 2011-10-31 19:30:30 -04:00
net_namespace.c netns: make nsid_lock per net 2015-05-17 23:41:11 -04:00
netclassid_cgroup.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
netevent.c netevent: remove automatic variable in register_netevent_notifier() 2015-05-31 00:03:21 -07:00
netpoll.c net: rename vlan_tx_* helpers since "tx" is misleading there 2015-01-13 17:51:08 -05:00
netprio_cgroup.c cgroup: rename cgroup_subsys->base_cftypes to ->legacy_cftypes 2014-07-15 11:05:09 -04:00
pktgen.c net: pktgen: kill the "Wait for kthread_stop" code in pktgen_thread_worker() 2015-07-09 15:05:32 -07:00
ptp_classifier.c net: filter: split 'struct sk_filter' into socket and bpf parts 2014-08-02 15:03:58 -07:00
request_sock.c net: convert syn_wait_lock to a spinlock 2015-03-23 16:52:26 -04:00
rtnetlink.c rtnetlink: verify IFLA_VF_INFO attributes before passing them to driver 2015-07-08 16:01:52 -07:00
scm.c net: introduce helper macro for_each_cmsghdr 2014-12-10 22:41:55 -05:00
secure_seq.c net: remove a sparse error in secure_dccpv6_sequence_number() 2015-05-25 22:55:37 -04:00
skbuff.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-13 23:56:52 -07:00
sock.c sock_diag: don't broadcast kernel sockets 2015-06-30 10:00:26 -07:00
sock_diag.c sock_diag: define destruction multicast groups 2015-06-15 19:49:22 -07:00
stream.c tcp: set SOCK_NOSPACE under memory pressure 2015-05-09 17:38:36 -04:00
sysctl_net_core.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-20 18:51:09 -04:00
timestamping.c net-timestamp: Make the clone operation stand-alone from phy timestamping 2014-09-05 17:43:45 -07:00
tso.c net: tso: fix unaligned access to crafted TCP header in helper API 2014-10-22 12:52:55 -04:00
utils.c net: fix inet_proto_csum_replace4() sparse errors 2015-05-25 22:56:47 -04:00