WARNING: ODEBUG bug in smc_ib_remove_dev

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    63623fd4 Merge tag 'for-linus' of git://git.kernel.org/pub..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12873645e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9833e26bab355358
dashboard link: https://syzkaller.appspot.com/bug?extid=b297c6825752e7a07272
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+b297c6825752e7a07272@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: work_struct hint: smc_ib_port_event_work+0x0/0x350 net/smc/smc_ib.c:312
WARNING: CPU: 0 PID: 14236 at lib/debugobjects.c:485 debug_print_object+0x168/0x250 lib/debugobjects.c:485
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 14236 Comm: kworker/u4:10 Not tainted 5.6.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound ib_unregister_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:485
Code: dd 00 e7 91 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 00 e7 91 88 48 c7 c7 60 dc 91 88 e8 07 6e 9f fd <0f> 0b 83 05 03 6c ff 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3
RSP: 0018:ffffc90001807ae0 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815ebe46 RDI: fffff52000300f4e
RBP: ffffc90001807b20 R08: ffff8880485a61c0 R09: ffffed1015d045c9
R10: ffffed1015d045c8 R11: ffff8880ae822e43 R12: 0000000000000001
R13: ffffffff89b7a220 R14: ffffffff814c8610 R15: ffff88806058e348
 __debug_check_no_obj_freed lib/debugobjects.c:967 [inline]
 debug_check_no_obj_freed+0x2d6/0x441 lib/debugobjects.c:998
 kfree+0xf8/0x2c0 mm/slab.c:3756
 smc_ib_remove_dev+0x1a9/0x2e0 net/smc/smc_ib.c:583
 remove_client_context+0xc7/0x120 drivers/infiniband/core/device.c:724
 disable_device+0x14c/0x230 drivers/infiniband/core/device.c:1268
 __ib_unregister_device+0x9c/0x190 drivers/infiniband/core/device.c:1435
 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1545
 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264
 worker_thread+0x98/0xe40 kernel/workqueue.c:2410
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..


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