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SubjectWARNING: bad unlock balance detected! (3)

syzbot found the following crash on:

HEAD commit: 40e196a906d9 Merge git://
git tree: upstream
console output:
kernel config:
dashboard link:
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386
syz repro:

IMPORTANT: if you fix the bug, please add the following tag to the commit:

Enabling of bearer <udp:
yz1> rejected, already enabled
Enabling of bearer <udp:
yz1> rejected, already enabled
WARNING: bad unlock balance detected!
5.0.0-rc7+ #80 Not tainted
kworker/1:1/22 is trying to release lock (
BUG: KASAN: slab-out-of-bounds in print_unlock_imbalance_bug
kernel/locking/lockdep.c:3383 [inline]
BUG: KASAN: slab-out-of-bounds in
print_unlock_imbalance_bug.cold+0x97/0x123 kernel/locking/lockdep.c:3368
Read of size 8 at addr ffff888216be498c by task kworker/1:1/22
Enabling of bearer <udp:
yz1> rejected, already enabled

CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.0.0-rc7+ #80
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: addrconf_dad_work (ipv6_addrconf)
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
__asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
print_unlock_imbalance_bug kernel/locking/lockdep.c:3383 [inline]
print_unlock_imbalance_bug.cold+0x97/0x123 kernel/locking/lockdep.c:3368
__lock_release kernel/locking/lockdep.c:3601 [inline]
lock_release+0x67e/0xa00 kernel/locking/lockdep.c:3860
process_one_work+0xa47/0x1790 kernel/workqueue.c:2180
worker_thread+0x98/0xe40 kernel/workqueue.c:2319
kthread+0x357/0x430 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 1:
save_stack+0x45/0xd0 mm/kasan/common.c:73
set_track mm/kasan/common.c:85 [inline]
__kasan_kmalloc mm/kasan/common.c:496 [inline]
__kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
kmalloc include/linux/slab.h:545 [inline]
kzalloc include/linux/slab.h:740 [inline]
__alloc_workqueue_key+0x79c/0xe00 kernel/workqueue.c:4099
addrconf_init+0x9a/0x3b1 net/ipv6/addrconf.c:6906
inet6_init+0x36c/0x6e1 net/ipv6/af_inet6.c:1022
do_one_initcall+0x109/0x796 init/main.c:887
do_initcall_level init/main.c:955 [inline]
do_initcalls init/main.c:963 [inline]
do_basic_setup init/main.c:981 [inline]
kernel_init_freeable+0x4da/0x5c9 init/main.c:1136
kernel_init+0x12/0x1c5 init/main.c:1054
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff888216be4780
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes to the right of
512-byte region [ffff888216be4780, ffff888216be4980)
The buggy address belongs to the page:
page:ffffea00085af900 count:1 mapcount:0 mapping:ffff88812c3f0940
flags: 0x6fffc0000000200(slab)
raw: 06fffc0000000200 ffffea0008581008 ffffea0008597888 ffff88812c3f0940
raw: ffff888216be4280 ffff888216be4000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888216be4880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888216be4900: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
> ffff888216be4980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888216be4a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888216be4a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

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