WARNING in __cancel_work_timer

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: dca73a65 Merge git://git.kernel.org/pub/scm/linux/kernel/g..
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10c97006a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=4937094fc643655f
dashboard link: https://syzkaller.appspot.com/bug?extid=2ed60998b94ce98cb9aa
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [a...@unstable.cc b.a.t...@lists.open-mesh.org
da...@davemloft.net linux-...@vger.kernel.org marekl...@neomailbox.ch
net...@vger.kernel.org s...@simonwunderlich.de net...@vger.kernel.org]

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+2ed609...@syzkaller.appspotmail.com

device hsr_slave_0 left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): Released all slaves
WARNING: CPU: 0 PID: 28851 at kernel/workqueue.c:619 set_work_data
kernel/workqueue.c:619 [inline]
WARNING: CPU: 0 PID: 28851 at kernel/workqueue.c:619 clear_work_data
kernel/workqueue.c:682 [inline]
WARNING: CPU: 0 PID: 28851 at kernel/workqueue.c:619
__cancel_work_timer+0x478/0x520 kernel/workqueue.c:3129
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 28851 Comm: kworker/u4:8 Not tainted 5.2.0-rc5+ #26
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+0x172/0x1f0 lib/dump_stack.c:113
panic+0x2cb/0x744 kernel/panic.c:219
__warn.cold+0x20/0x4d kernel/panic.c:576
report_bug+0x263/0x2b0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:179 [inline]
fixup_bug arch/x86/kernel/traps.c:174 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:set_work_data kernel/workqueue.c:619 [inline]
RIP: 0010:clear_work_data kernel/workqueue.c:682 [inline]
RIP: 0010:__cancel_work_timer+0x478/0x520 kernel/workqueue.c:3129
Code: e8 ed 3b 26 00 48 89 de 48 c7 c7 e0 11 d7 88 e8 7e 22 0a 00 e9 46 fc
ff ff e8 d4 3b 26 00 0f 0b e9 ce fc ff ff e8 c8 3b 26 00 <0f> 0b e9 f2 fd
ff ff e8 bc 3b 26 00 0f 0b e8 b5 3b 26 00 0f 0b e8
RSP: 0018:ffff88806561f880 EFLAGS: 00010293
RAX: ffff88806a476500 RBX: 0000000000000000 RCX: ffffffff814a84a8
RDX: 0000000000000000 RSI: ffffffff814a86b8 RDI: 0000000000000001
RBP: ffff88806561f980 R08: ffff88806a476500 R09: 0000000000000004
R10: ffffed1015d06c77 R11: ffff8880ae8363bb R12: ffff8880a9aa13a0
R13: 1ffff1100cac3f13 R14: 0000000000000000 R15: ffff88806561f958
cancel_delayed_work_sync+0x1b/0x20 kernel/workqueue.c:3259
batadv_dat_free+0x46/0xf0 net/batman-adv/distributed-arp-table.c:836
batadv_mesh_free+0x8a/0x170 net/batman-adv/main.c:253
batadv_softif_free+0x16/0x20 net/batman-adv/soft-interface.c:1046
netdev_run_todo+0x48b/0x7c0 net/core/dev.c:8992
rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:112
default_device_exit_batch+0x358/0x410 net/core/dev.c:9784
ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:168
cleanup_net+0x4e2/0xa40 net/core/net_namespace.c:575
process_one_work+0x989/0x1790 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x354/0x420 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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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.