linux-stable/net
Eric Dumazet 15fe076ede net/packet: fix a race in packet_bind() and packet_notifier()
syzbot reported crashes [1] and provided a C repro easing bug hunting.

When/if packet_do_bind() calls __unregister_prot_hook() and releases
po->bind_lock, another thread can run packet_notifier() and process an
NETDEV_UP event.

This calls register_prot_hook() and hooks again the socket right before
first thread is able to grab again po->bind_lock.

Fixes this issue by temporarily setting po->num to 0, as suggested by
David Miller.

[1]
dev_remove_pack: ffff8801bf16fa80 not found
------------[ cut here ]------------
kernel BUG at net/core/dev.c:7945!  ( BUG_ON(!list_empty(&dev->ptype_all)); )
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
device syz0 entered promiscuous mode
CPU: 0 PID: 3161 Comm: syzkaller404108 Not tainted 4.14.0+ #190
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cc57a500 task.stack: ffff8801cc588000
RIP: 0010:netdev_run_todo+0x772/0xae0 net/core/dev.c:7945
RSP: 0018:ffff8801cc58f598 EFLAGS: 00010293
RAX: ffff8801cc57a500 RBX: dffffc0000000000 RCX: ffffffff841f75b2
RDX: 0000000000000000 RSI: 1ffff100398b1ede RDI: ffff8801bf1f8810
device syz0 entered promiscuous mode
RBP: ffff8801cc58f898 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801bf1f8cd8
R13: ffff8801cc58f870 R14: ffff8801bf1f8780 R15: ffff8801cc58f7f0
FS:  0000000001716880(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020b13000 CR3: 0000000005e25000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:106
 tun_detach drivers/net/tun.c:670 [inline]
 tun_chr_close+0x49/0x60 drivers/net/tun.c:2845
 __fput+0x333/0x7f0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x199/0x270 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9bb/0x1ae0 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 SYSC_exit_group kernel/exit.c:979 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:977
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x44ad19

Fixes: 30f7ea1c2b ("packet: race condition in packet_bind")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Francesco Ruggeri <fruggeri@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-28 11:13:30 -05:00
..
6lowpan License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
9p Merge branch '9p-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-11-22 20:17:54 -10:00
802 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-12 09:17:05 +09:00
appletalk License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
ax25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
batman-adv batman-adv: Avoid spurious warnings from bat_v neigh_cmp implementation 2017-10-17 08:09:47 +02:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
bpf bpf: add meta pointer for direct access 2017-09-26 13:36:44 -07:00
bridge net: bridge: add vlan_tunnel to bridge port policies 2017-11-14 21:54:55 +09:00
caif License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ceph We have a set of file locking improvements from Zheng, rbd rw/ro 2017-11-21 05:38:32 -10:00
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2017-11-24 02:33:01 +09:00
dcb
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
decnet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
dns_resolver KEYS: Fix race between updating and finding a negative key 2017-10-18 09:12:40 +01:00
dsa net: dsa: fix 'increment on 0' warning 2017-11-26 04:23:10 +09:00
ethernet
hsr net: hsr: Convert timers to use timer_setup() 2017-10-25 13:00:27 +09:00
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ife MAINTAINERS: Update Yotam's E-mail 2017-11-01 12:19:03 +09:00
ipv4 net: accept UFO datagrams from tuntap and packet 2017-11-24 01:37:35 +09:00
ipv6 net: accept UFO datagrams from tuntap and packet 2017-11-24 01:37:35 +09:00
ipx Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
iucv
kcm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
key af_key: replace BUG_ON on WARN_ON in net_exit hook 2017-11-14 15:45:52 +09:00
l2tp l2tp: exit_net cleanup check added 2017-11-14 15:45:53 +09:00
l3mdev
lapb net/lapb: Convert timers to use timer_setup() 2017-10-18 12:39:36 +01:00
llc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
mac80211 mac80211: tear down RX aggregations first 2017-11-27 11:24:59 +01:00
mac802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
mpls Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
ncsi net/ncsi: Don't return error on normal response 2017-11-11 15:09:44 +09:00
netfilter netfilter: add ifdef around ctnetlink_proto_size 2017-11-16 10:49:00 +09:00
netlabel net/netlabel: Add list_next_rcu() in rcu_dereference(). 2017-11-18 10:32:41 +09:00
netlink netlink: remove unnecessary forward declaration 2017-11-14 21:51:14 +09:00
netrom Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-11-15 11:56:19 -08:00
nfc genetlink: fix genlmsg_nlhdr() 2017-11-16 10:49:00 +09:00
nsh openvswitch: enable NSH support 2017-11-08 16:12:33 +09:00
openvswitch openvswitch: fix the incorrect flow action alloc size 2017-11-26 18:34:59 -05:00
packet net/packet: fix a race in packet_bind() and packet_notifier() 2017-11-28 11:13:30 -05:00
phonet phonet: exit_net cleanup check added 2017-11-14 15:45:53 +09:00
psample MAINTAINERS: Update Yotam's E-mail 2017-11-01 12:19:03 +09:00
qrtr Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-10 10:00:18 +09:00
rds Merge branch 'akpm' (patches from Andrew) 2017-11-15 19:42:40 -08:00
rfkill
rose net: rose: mark expected switch fall-throughs 2017-10-22 02:02:26 +01:00
rxrpc rxrpc: Fix conn expiry timers 2017-11-24 10:18:42 +00:00
sched net: sched: crash on blocks with goto chain action 2017-11-25 23:57:20 +09:00
sctp sctp: remove extern from stream sched 2017-11-28 11:00:13 -05:00
smc net/smc: Fix preinitialization of buf_desc in __smc_buf_create() 2017-11-24 01:33:34 +09:00
strparser strparser: Use delayed work instead of timer for msg timeout 2017-10-25 10:37:11 +09:00
sunrpc Lots of good bugfixes, including: 2017-11-18 11:22:04 -08:00
switchdev net: bridge: Add/del switchdev object on host join/leave 2017-11-10 13:41:40 +09:00
tipc tipc: eliminate access after delete in group_filter_msg() 2017-11-27 14:44:45 -05:00
tls tls: don't override sk_write_space if tls_set_sw_offload fails. 2017-11-14 16:26:35 +09:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
vmw_vsock VSOCK: Don't call vsock_stream_has_data in atomic context 2017-11-26 04:21:50 +09:00
wimax License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
wireless cfg80211: select CRYPTO_SHA256 if needed 2017-11-24 22:18:37 +01:00
x25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec 2017-11-16 22:33:54 +09:00
compat.c net: compat: assert the size of cmsg copied in is as expected 2017-09-20 15:36:18 -07:00
Kconfig
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
socket.c kmemcheck: remove annotations 2017-11-15 18:21:04 -08:00
sysctl_net.c