linux/net
Anoob Soman 2bd624b461 packet: Do not call fanout_release from atomic contexts
Commit 6664498280 ("packet: call fanout_release, while UNREGISTERING a
netdev"), unfortunately, introduced the following issues.

1. calling mutex_lock(&fanout_mutex) (fanout_release()) from inside
rcu_read-side critical section. rcu_read_lock disables preemption, most often,
which prohibits calling sleeping functions.

[  ] include/linux/rcupdate.h:560 Illegal context switch in RCU read-side critical section!
[  ]
[  ] rcu_scheduler_active = 1, debug_locks = 0
[  ] 4 locks held by ovs-vswitchd/1969:
[  ]  #0:  (cb_lock){++++++}, at: [<ffffffff8158a6c9>] genl_rcv+0x19/0x40
[  ]  #1:  (ovs_mutex){+.+.+.}, at: [<ffffffffa04878ca>] ovs_vport_cmd_del+0x4a/0x100 [openvswitch]
[  ]  #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff81564157>] rtnl_lock+0x17/0x20
[  ]  #3:  (rcu_read_lock){......}, at: [<ffffffff81614165>] packet_notifier+0x5/0x3f0
[  ]
[  ] Call Trace:
[  ]  [<ffffffff813770c1>] dump_stack+0x85/0xc4
[  ]  [<ffffffff810c9077>] lockdep_rcu_suspicious+0x107/0x110
[  ]  [<ffffffff810a2da7>] ___might_sleep+0x57/0x210
[  ]  [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[  ]  [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[  ]  [<ffffffff810de93f>] ? vprintk_default+0x1f/0x30
[  ]  [<ffffffff81186e88>] ? printk+0x4d/0x4f
[  ]  [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[  ]  [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

2. calling mutex_lock(&fanout_mutex) inside spin_lock(&po->bind_lock).
"sleeping function called from invalid context"

[  ] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[  ] in_atomic(): 1, irqs_disabled(): 0, pid: 1969, name: ovs-vswitchd
[  ] INFO: lockdep is turned off.
[  ] Call Trace:
[  ]  [<ffffffff813770c1>] dump_stack+0x85/0xc4
[  ]  [<ffffffff810a2f52>] ___might_sleep+0x202/0x210
[  ]  [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[  ]  [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[  ]  [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[  ]  [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

3. calling dev_remove_pack(&fanout->prot_hook), from inside
spin_lock(&po->bind_lock) or rcu_read-side critical-section. dev_remove_pack()
-> synchronize_net(), which might sleep.

[  ] BUG: scheduling while atomic: ovs-vswitchd/1969/0x00000002
[  ] INFO: lockdep is turned off.
[  ] Call Trace:
[  ]  [<ffffffff813770c1>] dump_stack+0x85/0xc4
[  ]  [<ffffffff81186274>] __schedule_bug+0x64/0x73
[  ]  [<ffffffff8162b8cb>] __schedule+0x6b/0xd10
[  ]  [<ffffffff8162c5db>] schedule+0x6b/0x80
[  ]  [<ffffffff81630b1d>] schedule_timeout+0x38d/0x410
[  ]  [<ffffffff810ea3fd>] synchronize_sched_expedited+0x53d/0x810
[  ]  [<ffffffff810ea6de>] synchronize_rcu_expedited+0xe/0x10
[  ]  [<ffffffff8154eab5>] synchronize_net+0x35/0x50
[  ]  [<ffffffff8154eae3>] dev_remove_pack+0x13/0x20
[  ]  [<ffffffff8161077e>] fanout_release+0xbe/0xe0
[  ]  [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

4. fanout_release() races with calls from different CPU.

To fix the above problems, remove the call to fanout_release() under
rcu_read_lock(). Instead, call __dev_remove_pack(&fanout->prot_hook) and
netdev_run_todo will be happy that &dev->ptype_specific list is empty. In order
to achieve this, I moved dev_{add,remove}_pack() out of fanout_{add,release} to
__fanout_{link,unlink}. So, call to {,__}unregister_prot_hook() will make sure
fanout->prot_hook is removed as well.

Fixes: 6664498280 ("packet: call fanout_release, while UNREGISTERING a netdev")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Anoob Soman <anoob.soman@citrix.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-17 11:11:35 -05:00
..
6lowpan 6lowpan: ndisc: no overreact if no short address is available 2016-09-19 20:19:34 +02:00
9p IB/core: add support to create a unsafe global rkey to ib_create_pd 2016-09-23 13:47:44 -04:00
802 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
8021q Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
appletalk appletalk: use IS_ENABLED() instead of checking for built-in or module 2016-09-10 21:19:10 -07:00
atm net: atm: Fix warnings in net/atm/lec.c when !CONFIG_PROC_FS 2016-12-28 15:11:32 -05:00
ax25 ax25: Fix segfault after sock connection timeout 2017-01-16 14:39:58 -05:00
batman-adv batman-adv: Decrease hardif refcnt on fragmentation send error 2017-01-04 08:22:04 +01:00
bluetooth Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-12-16 10:24:44 -08:00
bridge bridge: netlink: call br_changelink() during br_dev_newlink() 2017-01-20 15:07:27 -05:00
caif Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-06 21:33:19 -05:00
can can: bcm: fix hrtimer/tasklet termination in bcm op removal 2017-01-30 11:05:04 +01:00
ceph libceph: make sure ceph_aes_crypt() IV is aligned 2017-01-18 17:58:45 +01:00
core net: neigh: Fix netevent NETEVENT_DELAY_PROBE_TIME_UPDATE notification 2017-02-15 12:38:43 -05:00
dcb net: dcb: set error code on failures 2016-12-03 23:54:25 -05:00
dccp tcp: don't annotate mark on control socket from tcp_v6_send_response() 2017-01-27 10:33:56 -05:00
decnet Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
dns_resolver
dsa net: dsa: Do not destroy invalid network devices 2017-02-08 14:50:51 -05:00
ethernet net: introduce device min_header_len 2017-02-08 13:56:37 -05:00
hsr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
ieee802154 Makefile: drop -D__CHECK_ENDIAN__ from cflags 2016-12-16 00:13:43 +02:00
ipv4 tcp: tcp_probe: use spin_lock_bh() 2017-02-14 22:19:39 -05:00
ipv6 ipv6: Handle IPv4-mapped src to in6addr_any dst. 2017-02-14 12:13:51 -05:00
ipx ktime: Get rid of the union 2016-12-25 17:21:22 +01:00
irda Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
iucv net/af_iucv: don't use paged skbs for TX on HiperSockets 2017-01-10 21:08:29 -05:00
kcm kcm: fix a null pointer dereference in kcm_sendmsg() 2017-02-14 13:06:37 -05:00
key netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
l2tp l2tp: do not use udp_ioctl() 2017-02-10 15:57:34 -05:00
l3mdev net: ipv6: Remove l3mdev_get_saddr6 2016-09-10 23:12:53 -07:00
lapb Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
llc net/llc: avoid BUG_ON() in skb_orphan() 2017-02-12 22:14:49 -05:00
mac80211 mac80211: Fix adding of mesh vendor IEs 2017-02-06 07:55:44 +01:00
mac802154 ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
mpls net: Specify the owning module for lwtunnel ops 2017-01-24 16:21:36 -05:00
ncsi net/ncsi: Improve HNCDSC AEN handler 2016-10-20 11:23:08 -04:00
netfilter netfilter: nf_tables: bump set->ndeact on set flush 2017-01-24 21:46:59 +01:00
netlabel netlabel: add CALIPSO to the list of built-in protocols 2017-01-06 22:20:45 -05:00
netlink Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
netrom
nfc genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
openvswitch openvswitch: maintain correct checksum state in conntrack actions 2017-01-15 22:15:16 -05:00
packet packet: Do not call fanout_release from atomic contexts 2017-02-17 11:11:35 -05:00
phonet netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
qrtr net: qrtr: Mark 'buf' as little endian 2017-01-10 20:45:04 -05:00
rds RDS: use rb_entry() 2016-12-20 14:22:49 -05:00
rfkill
rose Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
rxrpc rxrpc: abstract away knowledge of IDR internals 2016-12-14 16:04:10 -08:00
sched net/sched: matchall: Fix configuration race 2017-02-01 11:57:33 -05:00
sctp sctp: check af before verify address in sctp_addr_id2transport 2017-02-07 14:07:23 -05:00
strparser strparser: Propagate correct error code in strp_recv() 2016-10-12 01:51:49 -04:00
sunrpc svcrpc: fix oops in absence of krb5 module 2017-01-31 12:29:24 -05:00
switchdev Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-10-30 12:42:58 -04:00
tipc rhashtable: Revert nested table changes. 2017-02-15 22:29:51 -05:00
unix af_unix: move unix_mknod() out of bindlock 2017-01-24 14:30:56 -05:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-17 20:17:04 -08:00
wimax genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
wireless nl80211: Fix mesh HT operation check 2017-02-06 07:59:07 +01:00
x25 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
xfrm ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
compat.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
Kconfig cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig 2017-01-11 09:47:10 -05:00
Makefile strparser: Stream parser for messages 2016-08-17 19:36:23 -04:00
socket.c net: socket: Make unnecessarily global sockfs_setattr() static 2017-01-10 11:29:50 -05:00
sysctl_net.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2016-10-06 09:52:23 -07:00