WARNING in add_one_compat_dev

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    9d859289 docs: networking: add full DIM API
git tree:       net
console output: https://syzkaller.appspot.com/x/log.txt?x=11230b2be00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=94a7f1dec460ee83
dashboard link: https://syzkaller.appspot.com/bug?extid=283a75171cb87a7acb0e
compiler:       gcc (GCC) 9.0.0 20181231 (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+283a75171cb87a7acb0e@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
sysfs group 'power' not found for kobject 'syz1'
WARNING: CPU: 1 PID: 23343 at fs/sysfs/group.c:279 sysfs_remove_group fs/sysfs/group.c:279 [inline]
WARNING: CPU: 1 PID: 23343 at fs/sysfs/group.c:279 sysfs_remove_group+0x155/0x1b0 fs/sysfs/group.c:270
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 23343 Comm: syz-executor.4 Not tainted 5.6.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x35 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 fixup_bug arch/x86/kernel/traps.c:170 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:sysfs_remove_group fs/sysfs/group.c:279 [inline]
RIP: 0010:sysfs_remove_group+0x155/0x1b0 fs/sysfs/group.c:270
Code: 48 89 d9 49 8b 14 24 48 b8 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 01 00 75 41 48 8b 33 48 c7 c7 a0 e5 39 88 e8 13 b2 5e ff <0f> 0b eb 95 e8 f2 26 cb ff e9 d2 fe ff ff 48 89 df e8 e5 26 cb ff
RSP: 0018:ffffc90004a57a80 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffffffff889256e0 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff815ce2b1 RDI: fffff5200094af42
RBP: 0000000000000000 R08: ffff88808e0100c0 R09: ffffed1015ce66a9
R10: ffff8880ae733547 R11: ffffed1015ce66a8 R12: ffff88803efdb000
R13: ffffffff88925c80 R14: ffff888088b68e88 R15: ffff88803efdb518
 dpm_sysfs_remove+0x97/0xb0 drivers/base/power/sysfs.c:794
 device_del+0x18b/0xd30 drivers/base/core.c:2687
 add_one_compat_dev drivers/infiniband/core/device.c:921 [inline]
 add_one_compat_dev+0x59f/0x800 drivers/infiniband/core/device.c:857
 rdma_dev_init_net+0x2dc/0x480 drivers/infiniband/core/device.c:1122
 ops_init+0xaf/0x420 net/core/net_namespace.c:151
 setup_net+0x2de/0x860 net/core/net_namespace.c:341
 copy_net_ns+0x293/0x590 net/core/net_namespace.c:482
 create_new_namespaces+0x3fb/0xb30 kernel/nsproxy.c:108
 unshare_nsproxy_namespaces+0xbd/0x1f0 kernel/nsproxy.c:229
 ksys_unshare+0x43d/0x8e0 kernel/fork.c:2960
 __do_sys_unshare kernel/fork.c:3028 [inline]
 __se_sys_unshare kernel/fork.c:3026 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3026
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45c889
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f65f7741c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f65f77426d4 RCX: 000000000045c889
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000c40 R14: 00000000004ce690 R15: 000000000076bf0c
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.