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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Jiri Pirko <jiri@mellanox.com>,
	"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.19 23/45] net: fix ifindex collision during namespace removal
Date: Thu,  8 Aug 2019 21:05:09 +0200	[thread overview]
Message-ID: <20190808190455.035744605@linuxfoundation.org> (raw)
In-Reply-To: <20190808190453.827571908@linuxfoundation.org>

From: Jiri Pirko <jiri@mellanox.com>

[ Upstream commit 55b40dbf0e76b4bfb9d8b3a16a0208640a9a45df ]

Commit aca51397d014 ("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: aca51397d014 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/core/dev.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9510,6 +9510,8 @@ static void __net_exit default_device_ex
 
 		/* Push remaining network devices to init_net */
 		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
+		if (__dev_get_by_name(&init_net, fb_name))
+			snprintf(fb_name, IFNAMSIZ, "dev%%d");
 		err = dev_change_net_namespace(dev, &init_net, fb_name);
 		if (err) {
 			pr_emerg("%s: failed to move %s to init_net: %d\n",



  parent reply	other threads:[~2019-08-08 19:13 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-08 19:04 [PATCH 4.19 00/45] 4.19.66-stable review Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 01/45] scsi: fcoe: Embed fc_rport_priv in fcoe_rport structure Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 02/45] gcc-9: dont warn about uninitialized variable Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 03/45] driver core: Establish order of operations for device_add and device_del via bitflag Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 04/45] drivers/base: Introduce kill_device() Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 05/45] libnvdimm/bus: Prevent duplicate device_unregister() calls Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 06/45] libnvdimm/region: Register badblocks before namespaces Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 07/45] libnvdimm/bus: Prepare the nd_ioctl() path to be re-entrant Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 08/45] libnvdimm/bus: Fix wait_nvdimm_bus_probe_idle() ABBA deadlock Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 09/45] HID: wacom: fix bit shift for Cintiq Companion 2 Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 10/45] HID: Add quirk for HP X1200 PIXART OEM mouse Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 11/45] [PATCH] IB: directly cast the sockaddr union to aockaddr Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 12/45] atm: iphase: Fix Spectre v1 vulnerability Greg Kroah-Hartman
2019-08-08 19:04 ` [PATCH 4.19 13/45] bnx2x: Disable multi-cos feature Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 14/45] ife: error out when nla attributes are empty Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 15/45] ip6_gre: reload ipv6h in prepare_ip6gre_xmit_ipv6 Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 16/45] ip6_tunnel: fix possible use-after-free on xmit Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 17/45] ipip: validate header length in ipip_tunnel_xmit Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 18/45] mlxsw: spectrum: Fix error path in mlxsw_sp_module_init() Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 19/45] mvpp2: fix panic on module removal Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 20/45] mvpp2: refactor MTU change code Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 21/45] net: bridge: delete local fdb on device init failure Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 22/45] net: bridge: mcast: dont delete permanent entries when fast leave is enabled Greg Kroah-Hartman
2019-08-08 19:05 ` Greg Kroah-Hartman [this message]
2019-08-08 19:05 ` [PATCH 4.19 24/45] net/mlx5e: always initialize frag->last_in_page Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 25/45] net/mlx5: Use reversed order when unregister devices Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 26/45] net: phylink: Fix flow control for fixed-link Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 27/45] net: qualcomm: rmnet: Fix incorrect UL checksum offload logic Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 28/45] net: sched: Fix a possible null-pointer dereference in dequeue_func() Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 29/45] net sched: update vlan action for batched events operations Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 30/45] net: sched: use temporary variable for actions indexes Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 31/45] net/smc: do not schedule tx_work in SMC_CLOSED state Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 32/45] NFC: nfcmrvl: fix gpio-handling regression Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 33/45] ocelot: Cancel delayed work before wq destruction Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 34/45] tipc: compat: allow tipc commands without arguments Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 35/45] tun: mark small packets as owned by the tap sock Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 36/45] net/mlx5: Fix modify_cq_in alignment Greg Kroah-Hartman
2019-08-10 11:25   ` Pavel Machek
2019-08-11  6:17     ` Leon Romanovsky
2019-08-08 19:05 ` [PATCH 4.19 37/45] net/mlx5e: Prevent encap flow counter update async to user query Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 38/45] r8169: dont use MSI before RTL8168d Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 39/45] compat_ioctl: pppoe: fix PPPOEIOCSFWD handling Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 40/45] cgroup: Call cgroup_release() before __exit_signal() Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 41/45] cgroup: Implement css_task_iter_skip() Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 42/45] cgroup: Include dying leaders with live threads in PROCS iterations Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 43/45] cgroup: css_task_iter_skip()d iterators must be advanced before accessed Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 44/45] cgroup: Fix css_task_iter_advance_css_set() cset skip condition Greg Kroah-Hartman
2019-08-08 19:05 ` [PATCH 4.19 45/45] spi: bcm2835: Fix 3-wire mode if DMA is enabled Greg Kroah-Hartman
2019-08-09  0:37 ` [PATCH 4.19 00/45] 4.19.66-stable review shuah
2019-08-09  3:20 ` Naresh Kamboju
2019-08-09 15:37 ` Guenter Roeck

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