WSL2-Linux-Kernel/net
Jiri Pirko 55b40dbf0e net: fix ifindex collision during namespace removal
Commit aca51397d0 ("netns: Fix arbitrary net_device-s corruptions
on net_ns stop.") introduced a possibility to hit a BUG in case device
is returning back to init_net and two following conditions are met:
1) dev->ifindex value is used in a name of another "dev%d"
   device in init_net.
2) dev->name is used by another device in init_net.

Under real life circumstances this is hard to get. Therefore this has
been present happily for over 10 years. To reproduce:

$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 86:89:3f:86:61:29 brd ff:ff:ff:ff:ff:ff
3: enp0s2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff
$ ip netns add ns1
$ ip -n ns1 link add dummy1ns1 type dummy
$ ip -n ns1 link add dummy2ns1 type dummy
$ ip link set enp0s2 netns ns1
$ ip -n ns1 link set enp0s2 name dummy0
[  100.858894] virtio_net virtio0 dummy0: renamed from enp0s2
$ ip link add dev4 type dummy
$ ip -n ns1 a
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: dummy1ns1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 16:63:4c:38:3e:ff brd ff:ff:ff:ff:ff:ff
3: dummy2ns1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether aa:9e:86:dd:6b:5d brd ff:ff:ff:ff:ff:ff
4: dummy0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff
$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 86:89:3f:86:61:29 brd ff:ff:ff:ff:ff:ff
4: dev4: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 5a:e1:4a:b6:ec:f8 brd ff:ff:ff:ff:ff:ff
$ ip netns del ns1
[  158.717795] default_device_exit: failed to move dummy0 to init_net: -17
[  158.719316] ------------[ cut here ]------------
[  158.720591] kernel BUG at net/core/dev.c:9824!
[  158.722260] invalid opcode: 0000 [#1] SMP KASAN PTI
[  158.723728] CPU: 0 PID: 56 Comm: kworker/u2:1 Not tainted 5.3.0-rc1+ #18
[  158.725422] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
[  158.727508] Workqueue: netns cleanup_net
[  158.728915] RIP: 0010:default_device_exit.cold+0x1d/0x1f
[  158.730683] Code: 84 e8 18 c9 3e fe 0f 0b e9 70 90 ff ff e8 36 e4 52 fe 89 d9 4c 89 e2 48 c7 c6 80 d6 25 84 48 c7 c7 20 c0 25 84 e8 f4 c8 3e
[  158.736854] RSP: 0018:ffff8880347e7b90 EFLAGS: 00010282
[  158.738752] RAX: 000000000000003b RBX: 00000000ffffffef RCX: 0000000000000000
[  158.741369] RDX: 0000000000000000 RSI: ffffffff8128013d RDI: ffffed10068fcf64
[  158.743418] RBP: ffff888033550170 R08: 000000000000003b R09: fffffbfff0b94b9c
[  158.745626] R10: fffffbfff0b94b9b R11: ffffffff85ca5cdf R12: ffff888032f28000
[  158.748405] R13: dffffc0000000000 R14: ffff8880335501b8 R15: 1ffff110068fcf72
[  158.750638] FS:  0000000000000000(0000) GS:ffff888036000000(0000) knlGS:0000000000000000
[  158.752944] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  158.755245] CR2: 00007fe8b45d21d0 CR3: 00000000340b4005 CR4: 0000000000360ef0
[  158.757654] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  158.760012] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  158.762758] Call Trace:
[  158.763882]  ? dev_change_net_namespace+0xbb0/0xbb0
[  158.766148]  ? devlink_nl_cmd_set_doit+0x520/0x520
[  158.768034]  ? dev_change_net_namespace+0xbb0/0xbb0
[  158.769870]  ops_exit_list.isra.0+0xa8/0x150
[  158.771544]  cleanup_net+0x446/0x8f0
[  158.772945]  ? unregister_pernet_operations+0x4a0/0x4a0
[  158.775294]  process_one_work+0xa1a/0x1740
[  158.776896]  ? pwq_dec_nr_in_flight+0x310/0x310
[  158.779143]  ? do_raw_spin_lock+0x11b/0x280
[  158.780848]  worker_thread+0x9e/0x1060
[  158.782500]  ? process_one_work+0x1740/0x1740
[  158.784454]  kthread+0x31b/0x420
[  158.786082]  ? __kthread_create_on_node+0x3f0/0x3f0
[  158.788286]  ret_from_fork+0x3a/0x50
[  158.789871] ---[ end trace defd6c657c71f936 ]---
[  158.792273] RIP: 0010:default_device_exit.cold+0x1d/0x1f
[  158.795478] Code: 84 e8 18 c9 3e fe 0f 0b e9 70 90 ff ff e8 36 e4 52 fe 89 d9 4c 89 e2 48 c7 c6 80 d6 25 84 48 c7 c7 20 c0 25 84 e8 f4 c8 3e
[  158.804854] RSP: 0018:ffff8880347e7b90 EFLAGS: 00010282
[  158.807865] RAX: 000000000000003b RBX: 00000000ffffffef RCX: 0000000000000000
[  158.811794] RDX: 0000000000000000 RSI: ffffffff8128013d RDI: ffffed10068fcf64
[  158.816652] RBP: ffff888033550170 R08: 000000000000003b R09: fffffbfff0b94b9c
[  158.820930] R10: fffffbfff0b94b9b R11: ffffffff85ca5cdf R12: ffff888032f28000
[  158.825113] R13: dffffc0000000000 R14: ffff8880335501b8 R15: 1ffff110068fcf72
[  158.829899] FS:  0000000000000000(0000) GS:ffff888036000000(0000) knlGS:0000000000000000
[  158.834923] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  158.838164] CR2: 00007fe8b45d21d0 CR3: 00000000340b4005 CR4: 0000000000360ef0
[  158.841917] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  158.845149] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fix this by checking if a device with the same name exists in init_net
and fallback to original code - dev%d to allocate name - in case it does.

This was found using syzkaller.

Fixes: aca51397d0 ("netns: Fix arbitrary net_device-s corruptions on net_ns stop.")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-29 11:07:04 -07:00
..
6lowpan 6lowpan: no need to check return value of debugfs_create functions 2019-07-06 12:50:01 +02:00
9p 9p pull request for inclusion in 5.13 2019-07-12 17:31:19 -07:00
802 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-22 08:59:24 -04:00
appletalk treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372 2019-06-05 17:37:10 +02:00
atm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ax25 ax25: fix inconsistent lock state in ax25_destroy_timer 2019-06-16 14:22:37 -07:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-07-11 10:55:49 -07:00
bpf treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
bpfilter Kbuild updates for v5.3 2019-07-12 16:03:16 -07:00
bridge net: bridge: delete local fdb on device init failure 2019-07-29 09:50:05 -07:00
caif treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 194 2019-05-30 11:29:22 -07:00
can can: gw: Fix error path of cgw_module_init 2019-07-24 11:19:03 +02:00
ceph Lots of exciting things this time! 2019-07-18 11:05:25 -07:00
core net: fix ifindex collision during namespace removal 2019-07-29 11:07:04 -07:00
dcb treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201 2019-05-30 11:29:52 -07:00
dccp proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
decnet treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 53 2019-05-24 17:36:42 +02:00
dns_resolver Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
dsa net: flow_offload: add flow_block structure and use it 2019-07-19 21:27:45 -07:00
ethernet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 11:00:14 -07:00
hsr hsr: switch ->dellink() to ->ndo_uninit() 2019-07-11 14:37:45 -07:00
ieee802154 inet: fix various use-after-free in defrags units 2019-06-19 11:37:47 -04:00
ife treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf 2019-07-25 17:35:03 -07:00
ipv6 ip6_tunnel: fix possible use-after-free on xmit 2019-07-26 14:17:44 -07:00
iucv net/af_iucv: mark expected switch fall-throughs 2019-07-29 10:26:14 -07:00
kcm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
key Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
l2tp ipv6: elide flowlabel check if no exclusive leases exist 2019-07-08 19:38:03 -07:00
l3mdev ipv6: convert major tx path to use RT6_LOOKUP_F_DST_NOREF 2019-06-23 13:24:17 -07:00
lapb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-17 20:20:36 -07:00
llc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 281 2019-06-05 17:36:36 +02:00
mac80211 mac80211: don't warn about CW params when not using them 2019-07-20 21:40:32 +02:00
mac802154 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00
mpls proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
ncsi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
netfilter net: flow_offload: add flow_block structure and use it 2019-07-19 21:27:45 -07:00
netlabel treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
netlink net: remove empty netlink_tap_exit_net 2019-06-14 19:50:33 -07:00
netrom netrom: hold sock when setting skb->destructor 2019-07-24 15:49:05 -07:00
nfc nfc: fix potential illegal memory access 2019-07-08 12:46:24 -07:00
nsh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
openvswitch ovs: datapath: hide clang frame-overflow warnings 2019-07-24 15:45:11 -07:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-27 21:06:39 -07:00
phonet treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336 2019-06-05 17:37:07 +02:00
psample treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
qrtr treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284 2019-06-05 17:36:37 +02:00
rds net: rds: Fix possible null-pointer dereferences in rds_rdma_cm_event_handler_cmn() 2019-07-27 13:58:12 -07:00
rfkill treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
rose treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
rxrpc proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
sched net: sched: Fix a possible null-pointer dereference in dequeue_func() 2019-07-29 09:46:58 -07:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-19 10:06:06 -07:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-27 21:06:39 -07:00
strparser Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-22 08:59:24 -04:00
sunrpc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
switchdev treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tipc tipc: Fix a typo 2019-07-21 11:41:01 -07:00
tls bpf: sockmap/tls, close can race with map free 2019-07-22 16:04:17 +02:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-06-07 11:00:14 -07:00
vmw_vsock vsock/virtio: fix flush of works during the .remove() 2019-07-08 15:35:17 -07:00
wimax treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 268 2019-06-05 17:30:29 +02:00
wireless pci-v5.3-changes 2019-07-15 20:44:49 -07:00
x25 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 41 2019-05-24 17:27:12 +02:00
xdp xdp: fix potential deadlock on socket mutex 2019-07-12 15:02:21 +02:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-08 19:48:57 -07:00
Kconfig net: ipv4: move tcp_fastopen server side code to SipHash library 2019-06-17 13:56:26 -07:00
Makefile
compat.c uio: make import_iovec()/compat_import_iovec() return bytes on success 2019-05-31 15:30:03 -06:00
socket.c Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
sysctl_net.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00