====================
[ 80.643286] BUG: unable to handle kernel NULL pointer dereference at 0000000000000878
[ 80.670103] IP: [<ffffffff810832e4>] try_to_grab_pending+0x64/0x1f0
[ 80.691289] PGD 22c102067 PUD 235bf0067 PMD 0
[ 80.706611] Oops: 0002 [#1] SMP
[ 80.717836] Modules linked in: macvlan nfsd lockd nfs_acl exportfs auth_rpcgss sunrpc oid_registry ioatdma ixgbe(-) mdio igb dca
[ 80.757935] CPU: 37 PID: 6724 Comm: rmmod Not tainted 3.16.0-net-next-08-12-2014-FCoE+ #1
[ 80.785688] Hardware name: Intel Corporation S2600CO/S2600CO, BIOS SE5C600.86B.02.03.0003.041920141333 04/19/2014
[ 80.820310] task: ffff880235a9eae0 ti: ffff88022e844000 task.ti: ffff88022e844000
[ 80.845770] RIP: 0010:[<ffffffff810832e4>] [<ffffffff810832e4>] try_to_grab_pending+0x64/0x1f0
[ 80.875326] RSP: 0018:ffff88022e847b28 EFLAGS: 00010046
[ 80.893251] RAX: 0000000000037a6a RBX: 0000000000000878 RCX: 0000000000000000
[ 80.917187] RDX: ffff880235a9eae0 RSI: 0000000000000001 RDI: ffffffff810832db
[ 80.941125] RBP: ffff88022e847b58 R08: 0000000000000000 R09: 0000000000000000
[ 80.965056] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88022e847b70
[ 80.988994] R13: 0000000000000000 R14: ffff88022e847be8 R15: ffffffff81ebe440
[ 81.012929] FS: 00007fab90b07700(0000) GS:ffff88043f7a0000(0000) knlGS:0000000000000000
[ 81.040400] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 81.059757] CR2: 0000000000000878 CR3: 0000000235a42000 CR4: 00000000001407e0
[ 81.083689] Stack:
[ 81.090739] ffff880235a9eae0 0000000000000878 ffff88022e847b70 0000000000000000
[ 81.116253] ffff88022e847be8 ffffffff81ebe440 ffff88022e847b98 ffffffff810847f1
[ 81.141766] ffff88022e847b78 0000000000000286 ffff880234200000 0000000000000000
[ 81.167282] Call Trace:
[ 81.175768] [<ffffffff810847f1>] __cancel_work_timer+0x31/0x170
[ 81.195985] [<ffffffff8108494b>] cancel_work_sync+0xb/0x10
[ 81.214769] [<ffffffffa015ae68>] macvlan_port_destroy+0x28/0x60 [macvlan]
[ 81.237844] [<ffffffffa015b930>] macvlan_uninit+0x40/0x50 [macvlan]
[ 81.259209] [<ffffffff816bf6e2>] rollback_registered_many+0x1a2/0x2c0
[ 81.281140] [<ffffffff816bf81a>] unregister_netdevice_many+0x1a/0xb0
[ 81.302786] [<ffffffffa015a4ff>] macvlan_device_event+0x1ef/0x240 [macvlan]
[ 81.326439] [<ffffffff8108a13d>] notifier_call_chain+0x4d/0x70
[ 81.346366] [<ffffffff8108a201>] raw_notifier_call_chain+0x11/0x20
[ 81.367439] [<ffffffff816bf25b>] call_netdevice_notifiers_info+0x3b/0x70
[ 81.390228] [<ffffffff816bf2a1>] call_netdevice_notifiers+0x11/0x20
[ 81.411587] [<ffffffff816bf6bd>] rollback_registered_many+0x17d/0x2c0
[ 81.433518] [<ffffffff816bf925>] unregister_netdevice_queue+0x75/0x110
[ 81.455735] [<ffffffff816bfb2b>] unregister_netdev+0x1b/0x30
[ 81.475094] [<ffffffffa0039b50>] ixgbe_remove+0x170/0x1d0 [ixgbe]
[ 81.495886] [<ffffffff813512a2>] pci_device_remove+0x32/0x60
[ 81.515246] [<ffffffff814c75c4>] __device_release_driver+0x64/0xd0
[ 81.536321] [<ffffffff814c76f8>] driver_detach+0xc8/0xd0
[ 81.554530] [<ffffffff814c656e>] bus_remove_driver+0x4e/0xa0
[ 81.573888] [<ffffffff814c828b>] driver_unregister+0x2b/0x60
[ 81.593246] [<ffffffff8135143e>] pci_unregister_driver+0x1e/0xa0
[ 81.613749] [<ffffffffa005db18>] ixgbe_exit_module+0x1c/0x2e [ixgbe]
[ 81.635401] [<ffffffff810e738b>] SyS_delete_module+0x15b/0x1e0
[ 81.655334] [<ffffffff8187a395>] ? sysret_check+0x22/0x5d
[ 81.673833] [<ffffffff810abd2d>] ? trace_hardirqs_on_caller+0x11d/0x1e0
[ 81.696339] [<ffffffff8132bfde>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[ 81.717985] [<ffffffff8187a369>] system_call_fastpath+0x16/0x1b
[ 81.738199] Code: 00 48 83 3d 6e bb da 00 00 48 89 c2 0f 84 67 01 00 00 fa 66 0f 1f 44 00 00 49 89 14 24 e8 b5 4b 02 00 45 84 ed 0f 85 ac 00 00 00 <f0> 0f ba 2b 00 72 1d 31 c0 48 8b 5d d8 4c 8b 65 e0 4c 8b 6d e8
[ 81.807026] RIP [<ffffffff810832e4>] try_to_grab_pending+0x64/0x1f0
[ 81.828468] RSP <ffff88022e847b28>
[ 81.840384] CR2: 0000000000000878
[ 81.851731] ---[ end trace 9f6c7232e3464e11 ]---
====================
This bug could be triggered by these steps:
modprobe ixgbe ; modprobe macvlan
ip link add link p96p1 address 00:1B:21:6E:06:00 macvlan0 type macvlan
ip link add link p96p1 address 00:1B:21:6E:06:01 macvlan1 type macvlan
ip link add link p96p1 address 00:1B:21:6E:06:02 macvlan2 type macvlan
ip link add link p96p1 address 00:1B:21:6E:06:03 macvlan3 type macvlan
rmmod ixgbe
Reported-by: "Keller, Jacob E" <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/macvlan.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
@@ -45,10 +45,9 @@ struct macvlan_port {
struct sk_buff_head bc_queue;
struct work_struct bc_work;
bool passthru;
+ int count;
};
-#define MACVLAN_PORT_IS_EMPTY(port) list_empty(&port->vlans)
-
struct macvlan_skb_cb {
const struct macvlan_dev *src;
};
@@ -667,7 +666,8 @@ static void macvlan_uninit(struct net_device *dev)
free_percpu(vlan->pcpu_stats);
- if (MACVLAN_PORT_IS_EMPTY(port))
+ port->count -= 1;
+ if (!port->count)
macvlan_port_destroy(port->dev);
}
@@ -1020,12 +1020,13 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
vlan->flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]);
if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
- if (!MACVLAN_PORT_IS_EMPTY(port))
+ if (port->count)
return -EINVAL;
port->passthru = true;
eth_hw_addr_inherit(dev, lowerdev);
}
+ port->count += 1;
err = register_netdevice(dev);
if (err < 0)
goto destroy_port;
@@ -1043,7 +1044,8 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
unregister_netdev:
unregister_netdevice(dev);
destroy_port:
- if (MACVLAN_PORT_IS_EMPTY(port))
+ port->count -= 1;
+ if (!port->count)
macvlan_port_destroy(lowerdev);
return err;