WARNING in rollback_registered_many (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    042cb5647815 net: phy: Allow BCM54616S PHY to setup intern..
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=15c0102b400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8f559fee2fc3375a
dashboard link: https://syzkaller.appspot.com/bug?extid=40918e4d826fb2ff9b96
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+40918e4d826fb2ff9b96@xxxxxxxxxxxxxxxxxxxxxxxxx

device bridge_slave_0 left promiscuous mode
ïï: port 1(bridge_slave_0) entered disabled state
bond2 (unregistering): Released all slaves
bond1 (unregistering): Released all slaves
bond0 (unregistering): Released all slaves
WARNING: CPU: 1 PID: 9748 at net/core/dev.c:8022  
rollback_registered_many+0xeca/0x1250 net/core/dev.c:8022
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9748 Comm: kworker/u4:5 Not tainted 4.20.0-rc1+ #174
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 panic+0x2ad/0x55c kernel/panic.c:188
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969
RIP: 0010:rollback_registered_many+0xeca/0x1250 net/core/dev.c:8022
Code: 57 19 00 00 48 c7 c6 e0 01 bb 88 48 c7 c7 20 02 bb 88 c6 05 ea 2e ed  
03 01 e8 e2 c0 24 fb 0f 0b e9 a6 f9 ff ff e8 06 5f 5b fb <0f> 0b e9 7b f9  
ff ff e8 fa 5e 5b fb 0f 0b e9 ea f9 ff ff e8 ee 5e
RSP: 0018:ffff8801bbc17058 EFLAGS: 00010293
RAX: ffff880187848280 RBX: ffff880192c31240 RCX: ffffffff86242533
RDX: 0000000000000000 RSI: ffffffff86242bba RDI: 0000000000000001
RBP: ffff8801bbc172a0 R08: ffff880187848280 R09: fffffbfff13dee60
R10: fffffbfff13dee60 R11: ffffffff89ef7307 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff84889300 R15: ffff8801bbc17138
 unregister_netdevice_many+0xfa/0x4c0 net/core/dev.c:9107
 default_device_exit_batch+0x43a/0x540 net/core/dev.c:9576
 ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..


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