linux/net
WANG Cong 86e363dc3b net_sched: invoke ->attach() after setting dev->qdisc
For mq qdisc, we add per tx queue qdisc to root qdisc
for display purpose, however, that happens too early,
before the new dev->qdisc is finally set, this causes
q->list points to an old root qdisc which is going to be
freed right before assigning with a new one.

Fix this by moving ->attach() after setting dev->qdisc.

For the record, this fixes the following crash:

 ------------[ cut here ]------------
 WARNING: CPU: 1 PID: 975 at lib/list_debug.c:59 __list_del_entry+0x5a/0x98()
 list_del corruption. prev->next should be ffff8800d1998ae8, but was 6b6b6b6b6b6b6b6b
 CPU: 1 PID: 975 Comm: tc Not tainted 4.1.0-rc4+ #1019
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000009 ffff8800d73fb928 ffffffff81a44e7f 0000000047574756
  ffff8800d73fb978 ffff8800d73fb968 ffffffff810790da ffff8800cfc4cd20
  ffffffff814e725b ffff8800d1998ae8 ffffffff82381250 0000000000000000
 Call Trace:
  [<ffffffff81a44e7f>] dump_stack+0x4c/0x65
  [<ffffffff810790da>] warn_slowpath_common+0x9c/0xb6
  [<ffffffff814e725b>] ? __list_del_entry+0x5a/0x98
  [<ffffffff81079162>] warn_slowpath_fmt+0x46/0x48
  [<ffffffff81820eb0>] ? dev_graft_qdisc+0x5e/0x6a
  [<ffffffff814e725b>] __list_del_entry+0x5a/0x98
  [<ffffffff814e72a7>] list_del+0xe/0x2d
  [<ffffffff81822f05>] qdisc_list_del+0x1e/0x20
  [<ffffffff81820cd1>] qdisc_destroy+0x30/0xd6
  [<ffffffff81822676>] qdisc_graft+0x11d/0x243
  [<ffffffff818233c1>] tc_get_qdisc+0x1a6/0x1d4
  [<ffffffff810b5eaf>] ? mark_lock+0x2e/0x226
  [<ffffffff817ff8f5>] rtnetlink_rcv_msg+0x181/0x194
  [<ffffffff817ff72e>] ? rtnl_lock+0x17/0x19
  [<ffffffff817ff72e>] ? rtnl_lock+0x17/0x19
  [<ffffffff817ff774>] ? __rtnl_unlock+0x17/0x17
  [<ffffffff81855dc6>] netlink_rcv_skb+0x4d/0x93
  [<ffffffff817ff756>] rtnetlink_rcv+0x26/0x2d
  [<ffffffff818544b2>] netlink_unicast+0xcb/0x150
  [<ffffffff81161db9>] ? might_fault+0x59/0xa9
  [<ffffffff81854f78>] netlink_sendmsg+0x4fa/0x51c
  [<ffffffff817d6e09>] sock_sendmsg_nosec+0x12/0x1d
  [<ffffffff817d8967>] sock_sendmsg+0x29/0x2e
  [<ffffffff817d8cf3>] ___sys_sendmsg+0x1b4/0x23a
  [<ffffffff8100a1b8>] ? native_sched_clock+0x35/0x37
  [<ffffffff810a1d83>] ? sched_clock_local+0x12/0x72
  [<ffffffff810a1fd4>] ? sched_clock_cpu+0x9e/0xb7
  [<ffffffff810def2a>] ? current_kernel_time+0xe/0x32
  [<ffffffff810b4bc5>] ? lock_release_holdtime.part.29+0x71/0x7f
  [<ffffffff810ddebf>] ? read_seqcount_begin.constprop.27+0x5f/0x76
  [<ffffffff810b6292>] ? trace_hardirqs_on_caller+0x17d/0x199
  [<ffffffff811b14d5>] ? __fget_light+0x50/0x78
  [<ffffffff817d9808>] __sys_sendmsg+0x42/0x60
  [<ffffffff817d9838>] SyS_sendmsg+0x12/0x1c
  [<ffffffff81a50e97>] system_call_fastpath+0x12/0x6f
 ---[ end trace ef29d3fb28e97ae7 ]---

For long term, we probably need to clean up the qdisc_graft() code
in case it hides other bugs like this.

Fixes: 95dc19299f ("pkt_sched: give visibility to mq slave qdiscs")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-27 14:09:55 -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 unix/caif: sk_socket can disappear when state is unlocked 2015-05-26 23:19:29 -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: fix AP_VLAN crypto tailroom calculation 2015-05-20 15:10:11 +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: invoke ->attach() after setting dev->qdisc 2015-05-27 14:09:55 -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 unix/caif: sk_socket can disappear when state is unlocked 2015-05-26 23:19:29 -04:00
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 kconfig: use bool instead of boolean for type definition attributes 2015-01-07 13:08:04 +01:00
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