linux/net
David Ahern 51161aa98d net: Fix suspicious RCU usage in fib_rebalance
This command:
  ip route add 192.168.1.0/24 nexthop via 10.2.1.5 dev eth1 nexthop via 10.2.2.5 dev eth2

generated this suspicious RCU usage message:

[ 63.249262]
[ 63.249939] ===============================
[ 63.251571] [ INFO: suspicious RCU usage. ]
[ 63.253250] 4.3.0-rc3+ #298 Not tainted
[ 63.254724] -------------------------------
[ 63.256401] ../include/linux/inetdevice.h:205 suspicious rcu_dereference_check() usage!
[ 63.259450]
[ 63.259450] other info that might help us debug this:
[ 63.259450]
[ 63.262297]
[ 63.262297] rcu_scheduler_active = 1, debug_locks = 1
[ 63.264647] 1 lock held by ip/2870:
[ 63.265896] #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff813ebfb7>] rtnl_lock+0x12/0x14
[ 63.268858]
[ 63.268858] stack backtrace:
[ 63.270409] CPU: 4 PID: 2870 Comm: ip Not tainted 4.3.0-rc3+ #298
[ 63.272478] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 63.275745] 0000000000000001 ffff8800b8c9f8b8 ffffffff8125f73c ffff88013afcf301
[ 63.278185] ffff8800bab7a380 ffff8800b8c9f8e8 ffffffff8107bf30 ffff8800bb728000
[ 63.280634] ffff880139fe9a60 0000000000000000 ffff880139fe9a00 ffff8800b8c9f908
[ 63.283177] Call Trace:
[ 63.283959] [<ffffffff8125f73c>] dump_stack+0x4c/0x68
[ 63.285593] [<ffffffff8107bf30>] lockdep_rcu_suspicious+0xfa/0x103
[ 63.287500] [<ffffffff8144d752>] __in_dev_get_rcu+0x48/0x4f
[ 63.289169] [<ffffffff8144d797>] fib_rebalance+0x3e/0x127
[ 63.290753] [<ffffffff8144d986>] ? rcu_read_unlock+0x3e/0x5f
[ 63.292442] [<ffffffff8144ea45>] fib_create_info+0xaf9/0xdcc
[ 63.294093] [<ffffffff8106c12f>] ? sched_clock_local+0x12/0x75
[ 63.295791] [<ffffffff8145236a>] fib_table_insert+0x8c/0x451
[ 63.297493] [<ffffffff8144bf9c>] ? fib_get_table+0x36/0x43
[ 63.299109] [<ffffffff8144c3ca>] inet_rtm_newroute+0x43/0x51
[ 63.300709] [<ffffffff813ef684>] rtnetlink_rcv_msg+0x182/0x195
[ 63.302334] [<ffffffff8107d04c>] ? trace_hardirqs_on+0xd/0xf
[ 63.303888] [<ffffffff813ebfb7>] ? rtnl_lock+0x12/0x14
[ 63.305346] [<ffffffff813ef502>] ? __rtnl_unlock+0x12/0x12
[ 63.306878] [<ffffffff81407c4c>] netlink_rcv_skb+0x3d/0x90
[ 63.308437] [<ffffffff813ec00e>] rtnetlink_rcv+0x21/0x28
[ 63.309916] [<ffffffff81407742>] netlink_unicast+0xfa/0x17f
[ 63.311447] [<ffffffff81407a5e>] netlink_sendmsg+0x297/0x2dc
[ 63.313029] [<ffffffff813c6cd4>] sock_sendmsg_nosec+0x12/0x1d
[ 63.314597] [<ffffffff813c835b>] ___sys_sendmsg+0x196/0x21b
[ 63.316125] [<ffffffff8100bf9f>] ? native_sched_clock+0x1f/0x3c
[ 63.317671] [<ffffffff8106c12f>] ? sched_clock_local+0x12/0x75
[ 63.319185] [<ffffffff8106c397>] ? sched_clock_cpu+0x9d/0xb6
[ 63.320693] [<ffffffff8107e2d7>] ? __lock_is_held+0x32/0x54
[ 63.322145] [<ffffffff81159fcb>] ? __fget_light+0x4b/0x77
[ 63.323541] [<ffffffff813c8726>] __sys_sendmsg+0x3d/0x5b
[ 63.324947] [<ffffffff813c8751>] SyS_sendmsg+0xd/0x19
[ 63.326274] [<ffffffff814c8f57>] entry_SYSCALL_64_fastpath+0x12/0x6f

It looks like all of the code paths to fib_rebalance are under rtnl.

Fixes: 0e884c78ee ("ipv4: L3 hash-based multipath")
Cc: Peter Nørlund <pch@ordbogen.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 00:57:55 -07:00
..
6lowpan 6lowpan: move shared settings to lowpan_netdev_setup 2015-10-08 14:25:34 +02:00
9p net/9p: Remove ib_get_dma_mr calls 2015-08-30 18:12:36 -04:00
802
8021q net: 8021q: convert to using IFF_NO_QUEUE 2015-08-18 11:55:06 -07:00
appletalk
atm atm: deal with setting entry before mkip was called 2015-09-17 22:13:32 -07:00
ax25 NET: AX.25: Stop heartbeat timer on disconnect. 2015-07-15 15:59:58 -07:00
batman-adv batman-adv: turn batadv_neigh_node_get() into local function 2015-08-27 20:15:34 +02:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next 2015-10-11 05:15:30 -07:00
bridge bridge: defer switchdev fdb del call in fdb_del_external_learn 2015-10-15 06:09:50 -07:00
caif net: caif: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
can can: avoid using timeval for uapi 2015-10-13 17:42:34 +02:00
ceph libceph: don't access invalid memory in keepalive2 path 2015-09-17 20:14:15 +03:00
core net: SO_INCOMING_CPU setsockopt() support 2015-10-12 19:28:20 -07:00
dcb net/dcb: make dcbnl.c explicitly non-modular 2015-10-09 07:52:27 -07:00
dccp tcp/dccp: add inet_csk_reqsk_queue_drop_and_put() helper 2015-10-16 00:52:18 -07:00
decnet dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
dns_resolver
dsa switchdev: remove pointers from switchdev objects 2015-10-15 06:09:49 -07:00
ethernet net: help compiler generate better code in eth_get_headlen 2015-09-28 22:51:15 -07:00
hsr net: hsr: convert to using IFF_NO_QUEUE 2015-08-18 11:55:07 -07:00
ieee802154 6lowpan: move shared settings to lowpan_netdev_setup 2015-10-08 14:25:34 +02:00
ipv4 net: Fix suspicious RCU usage in fib_rebalance 2015-10-16 00:57:55 -07:00
ipv6 tcp/dccp: add inet_csk_reqsk_queue_drop_and_put() helper 2015-10-16 00:52:18 -07:00
ipx
irda
iucv s390/iucv: do not use arrays as argument 2015-09-21 16:03:04 -07:00
key net: Fix RCU splat in af_key 2015-08-24 14:48:10 -07:00
l2tp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-10-02 07:21:25 -07:00
l3mdev net: Add netif_is_l3_slave 2015-10-07 04:27:43 -07:00
lapb
llc tcp: fix recv with flags MSG_WAITALL | MSG_PEEK 2015-07-27 01:06:53 -07:00
mac80211 For the current cycle, we have the following right now: 2015-10-07 04:29:18 -07:00
mac802154 ieee802154: change mtu size behaviour 2015-09-30 13:21:32 +02:00
mpls dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
netfilter ipv4: Pass struct net into ip_defrag and ip_check_defrag 2015-10-12 19:44:16 -07:00
netlabel
netlink net/netlink: lockdep_genl_is_held can be boolean 2015-10-09 07:48:59 -07:00
netrom netfilter: Remove spurios included of netfilter.h 2015-06-18 21:14:32 +02:00
nfc nfc: netlink: Add capability to reply to vendor_cmd with data 2015-08-20 22:00:11 +02:00
openvswitch ipv6: Pass struct net into nf_ct_frag6_gather 2015-10-12 19:44:17 -07:00
packet ipv4: Pass struct net into ip_defrag and ip_check_defrag 2015-10-12 19:44:16 -07:00
phonet
rds RDS-TCP: Reset tcp callbacks if re-using an outgoing socket in rds_tcp_accept_one() 2015-10-13 04:22:41 -07:00
rfkill rfkill: Copy "all" global state to other types 2015-09-04 14:26:56 +02:00
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-06-24 02:58:51 -07:00
rxrpc rxrpc: Replace get_seconds with ktime_get_seconds 2015-09-20 21:53:56 -07:00
sched net: synack packets can be attached to request sockets 2015-10-11 05:05:06 -07:00
sctp net: sctp: avoid incorrect time_t use 2015-10-05 03:16:48 -07:00
sunrpc Changes for 4.3-rc4 2015-10-01 16:38:52 -04:00
switchdev switchdev: assert rtnl mutex when going over lower netdevs 2015-10-15 06:09:53 -07:00
tipc tipc: update node FSM when peer RESET message is received 2015-10-15 23:55:23 -07:00
unix af_unix: return data from multiple SKBs on recv() with MSG_PEEK flag 2015-09-29 13:47:08 -07:00
vmw_vsock
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless For the current cycle, we have the following right now: 2015-10-07 04:29:18 -07:00
x25
xfrm dst: Pass net into dst->output 2015-10-08 04:27:03 -07:00
compat.c
Kconfig net: Introduce L3 Master device abstraction 2015-09-29 20:40:32 -07:00
Makefile net: Introduce L3 Master device abstraction 2015-09-29 20:40:32 -07:00
socket.c
sysctl_net.c