• Nikolay Aleksandrov's avatar
    ip6mr: fix notification device destruction · 723b929c
    Nikolay Aleksandrov authored
    Andrey Konovalov reported a BUG caused by the ip6mr code which is caused
    because we call unregister_netdevice_many for a device that is already
    being destroyed. In IPv4's ipmr that has been resolved by two commits
    long time ago by introducing the "notify" parameter to the delete
    function and avoiding the unregister when called from a notifier, so
    let's do the same for ip6mr.
    
    The trace from Andrey:
    ------------[ cut here ]------------
    kernel BUG at net/core/dev.c:6813!
    invalid opcode: 0000 [#1] SMP KASAN
    Modules linked in:
    CPU: 1 PID: 1165 Comm: kworker/u4:3 Not tainted 4.11.0-rc7+ #251
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
    01/01/2011
    Workqueue: netns cleanup_net
    task: ffff880069208000 task.stack: ffff8800692d8000
    RIP: 0010:rollback_registered_many+0x348/0xeb0 net/core/dev.c:6813
    RSP: 0018:ffff8800692de7f0 EFLAGS: 00010297
    RAX: ffff880069208000 RBX: 0000000000000002 RCX: 0000000000000001
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88006af90569
    RBP: ffff8800692de9f0 R08: ffff8800692dec60 R09: 0000000000000000
    R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006af90070
    R13: ffff8800692debf0 R14: dffffc0000000000 R15: ffff88006af90000
    FS:  0000000000000000(0000) GS:ffff88006cb00000(0000)
    knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fe7e897d870 CR3: 00000000657e7000 CR4: 00000000000006e0
    Call Trace:
     unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
     unregister_netdevice_many+0xc8/0x120 net/core/dev.c:7880
     ip6mr_device_event+0x362/0x3f0 net/ipv6/ip6mr.c:1346
     notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93
     __raw_notifier_call_chain kernel/notifier.c:394
     raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
     call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1647
     call_netdevice_notifiers net/core/dev.c:1663
     rollback_registered_many+0x919/0xeb0 net/core/dev.c:6841
     unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
     unregister_netdevice_many net/core/dev.c:7880
     default_device_exit_batch+0x4fa/0x640 net/core/dev.c:8333
     ops_exit_list.isra.4+0x100/0x150 net/core/net_namespace.c:144
     cleanup_net+0x5a8/0xb40 net/core/net_namespace.c:463
     process_one_work+0xc04/0x1c10 kernel/workqueue.c:2097
     worker_thread+0x223/0x19c0 kernel/workqueue.c:2231
     kthread+0x35e/0x430 kernel/kthread.c:231
     ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
    Code: 3c 32 00 0f 85 70 0b 00 00 48 b8 00 02 00 00 00 00 ad de 49 89
    47 78 e9 93 fe ff ff 49 8d 57 70 49 8d 5f 78 eb 9e e8 88 7a 14 fe <0f>
    0b 48 8b 9d 28 fe ff ff e8 7a 7a 14 fe 48 b8 00 00 00 00 00
    RIP: rollback_registered_many+0x348/0xeb0 RSP: ffff8800692de7f0
    ---[ end trace e0b29c57e9b3292c ]---
    Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Signed-off-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
    Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    723b929c
ip6mr.c 57.4 KB