linux/net
Eric Dumazet 93a33a584e bridge: fix lockdep splat
Following lockdep splat was reported :

[   29.382286] ===============================
[   29.382315] [ INFO: suspicious RCU usage. ]
[   29.382344] 4.1.0-0.rc0.git11.1.fc23.x86_64 #1 Not tainted
[   29.382380] -------------------------------
[   29.382409] net/bridge/br_private.h:626 suspicious
rcu_dereference_check() usage!
[   29.382455]
               other info that might help us debug this:

[   29.382507]
               rcu_scheduler_active = 1, debug_locks = 0
[   29.382549] 2 locks held by swapper/0/0:
[   29.382576]  #0:  (((&p->forward_delay_timer))){+.-...}, at:
[<ffffffff81139f75>] call_timer_fn+0x5/0x4f0
[   29.382660]  #1:  (&(&br->lock)->rlock){+.-...}, at:
[<ffffffffa0450dc1>] br_forward_delay_timer_expired+0x31/0x140
[bridge]
[   29.382754]
               stack backtrace:
[   29.382787] CPU: 0 PID: 0 Comm: swapper/0 Not tainted
4.1.0-0.rc0.git11.1.fc23.x86_64 #1
[   29.382838] Hardware name: LENOVO 422916G/LENOVO, BIOS A1KT53AUS 04/07/2015
[   29.382882]  0000000000000000 3ebfc20364115825 ffff880666603c48
ffffffff81892d4b
[   29.382943]  0000000000000000 ffffffff81e124e0 ffff880666603c78
ffffffff8110bcd7
[   29.383004]  ffff8800785c9d00 ffff88065485ac58 ffff880c62002800
ffff880c5fc88ac0
[   29.383065] Call Trace:
[   29.383084]  <IRQ>  [<ffffffff81892d4b>] dump_stack+0x4c/0x65
[   29.383130]  [<ffffffff8110bcd7>] lockdep_rcu_suspicious+0xe7/0x120
[   29.383178]  [<ffffffffa04520f9>] br_fill_ifinfo+0x4a9/0x6a0 [bridge]
[   29.383225]  [<ffffffffa045266b>] br_ifinfo_notify+0x11b/0x4b0 [bridge]
[   29.383271]  [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge]
[   29.383320]  [<ffffffffa0450de8>]
br_forward_delay_timer_expired+0x58/0x140 [bridge]
[   29.383371]  [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge]
[   29.383416]  [<ffffffff8113a033>] call_timer_fn+0xc3/0x4f0
[   29.383454]  [<ffffffff81139f75>] ? call_timer_fn+0x5/0x4f0
[   29.383493]  [<ffffffff8110a90f>] ? lock_release_holdtime.part.29+0xf/0x200
[   29.383541]  [<ffffffffa0450d90>] ? br_hold_timer_expired+0x70/0x70 [bridge]
[   29.383587]  [<ffffffff8113a6a4>] run_timer_softirq+0x244/0x490
[   29.383629]  [<ffffffff810b68cc>] __do_softirq+0xec/0x670
[   29.383666]  [<ffffffff810b70d5>] irq_exit+0x145/0x150
[   29.383703]  [<ffffffff8189f506>] smp_apic_timer_interrupt+0x46/0x60
[   29.383744]  [<ffffffff8189d523>] apic_timer_interrupt+0x73/0x80
[   29.383782]  <EOI>  [<ffffffff816f131f>] ? cpuidle_enter_state+0x5f/0x2f0
[   29.383832]  [<ffffffff816f131b>] ? cpuidle_enter_state+0x5b/0x2f0

Problem here is that br_forward_delay_timer_expired() is a timer
handler, calling br_ifinfo_notify() which assumes either rcu_read_lock()
or RTNL are held.

Simplest fix seems to add rcu read lock section.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Reported-by: Dominick Grift <dac.override@gmail.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-22 16:23:56 -04:00
..
6lowpan 6lowpan: nhc: add other known rfc6282 compressions 2015-02-14 23:08:44 +01:00
9p 9p: patches for 4.1 merge window 2015-04-18 17:45:30 -04:00
802 net: Kill dev_rebuild_header 2015-03-02 16:43:41 -05:00
8021q vlan: Correctly propagate promisc|allmulti flags in notifier. 2015-05-14 00:54:32 -04:00
appletalk appletalk: Use eth_<foo>_addr instead of memset 2015-03-03 17:01:37 -05:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-04-15 09:00:47 -07:00
ax25 ax25: Fix the build when CONFIG_INET is disabled 2015-03-05 13:17:39 -05:00
batman-adv dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
bluetooth Bluetooth: Fix remote name event return directly. 2015-05-14 10:35:04 +02:00
bridge bridge: fix lockdep splat 2015-05-22 16:23:56 -04:00
caif Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-20 18:51:09 -04:00
can can: introduce new raw socket option to join the given CAN filters 2015-04-01 11:28:22 +02:00
ceph crush: straw2 bucket type with an efficient 64-bit crush_ln() 2015-04-22 18:33:43 +03:00
core net: core: 'ethtool' issue with querying phy settings 2015-05-22 16:14:17 -04:00
dcb net/dcb: Add IEEE QCN attribute 2015-03-06 21:50:02 -05:00
dccp inet: fix possible panic in reqsk_queue_unlink() 2015-04-24 11:39:15 -04:00
decnet netfilter: Pass socket pointer down through okfn(). 2015-04-07 15:25:55 -04:00
dns_resolver
dsa net: dsa: Fix scope of eeprom-length property 2015-04-29 15:35:04 -04:00
ethernet ethernet: Use eth_<foo>_addr instead of memset 2015-03-03 17:01:38 -05:00
hsr net/hsr: Fix NULL pointer dereference and refcnt bugs when deleting a HSR interface. 2015-03-01 13:40:23 -05:00
ieee802154 ieee802154: trace: fix endian convertion 2015-04-30 18:48:11 +02:00
ipv4 ipv4: fill in table id when replacing a route 2015-05-22 14:33:17 -04:00
ipv6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-05-22 14:25:45 -04:00
ipx net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
irda Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-03-09 23:38:02 -04:00
iucv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-02 16:16:53 -04:00
key xfrm: simplify xfrm_address_t use 2015-03-31 13:58:35 -04:00
l2tp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-06 22:34:15 -04:00
lapb
llc net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
mac80211 mac80211: move WEP tailroom size check 2015-05-11 14:51:29 +02:00
mac802154 Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2015-05-09 15:51:00 -04:00
mpls mpls: Change reserved label names to be consistent with netbsd 2015-05-09 22:29:50 -04:00
netfilter netfilter: nfnetlink_{log,queue}: Register pernet in first place 2015-05-20 13:46:48 +02:00
netlabel netlink: implement nla_put_in_addr and nla_put_in6_addr 2015-03-31 13:58:35 -04:00
netlink netlink: Reset portid after netlink_insert failure 2015-05-16 17:08:57 -04:00
netrom net: Kill dev_rebuild_header 2015-03-02 16:43:41 -05:00
nfc nfc: Fix portid type in urelease_work 2015-04-13 16:35:16 -04:00
openvswitch Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-04-15 09:00:47 -07:00
packet af_packet / TX_RING not fully non-blocking (w/ MSG_DONTWAIT). 2015-05-10 19:40:08 -04:00
phonet net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
rds net/rds: RDS-TCP: only initiate reconnect attempt on outgoing TCP socket. 2015-05-09 16:03:28 -04:00
rfkill Last round of updates for net-next: 2015-02-04 14:57:45 -08:00
rose net: Kill dev_rebuild_header 2015-03-02 16:43:41 -05:00
rxrpc new helper: msg_data_left() 2015-04-11 15:53:35 -04:00
sched net: sched: fix call_rcu() race on classifier module unloads 2015-05-21 18:48:18 -04:00
sctp sctp: avoid to repeatedly declare external variables 2015-03-25 11:40:16 -04:00
sunrpc svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures 2015-05-04 12:02:40 -04:00
switchdev rename RTNH_F_EXTERNAL to RTNH_F_OFFLOAD 2015-05-14 22:45:39 -04:00
tipc tipc: fix problem with parallel link synchronization mechanism 2015-04-29 15:08:59 -04:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-27 14:05:19 -07:00
vmw_vsock net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
wimax
wireless cfg80211: don't allow disabling WEXT if it's required 2015-04-08 09:19:29 +02:00
x25 net: Remove iocb argument from sendmsg and recvmsg 2015-03-02 13:06:31 -05:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-04-14 15:44:14 -04:00
compat.c net: switch importing msghdr from userland to {compat_,}import_iovec() 2015-04-09 00:02:26 -04:00
Kconfig
Makefile mpls: Refactor how the mpls module is built 2015-03-04 00:26:06 -05:00
socket.c VFS: net/: d_inode() annotations 2015-04-15 15:06:56 -04:00
sysctl_net.c