------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 26025 at lib/refcount.c:28 refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 26025 Comm: kworker/0:0 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events do_enable_set
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:105 [inline]
 fixup_bug arch/x86/kernel/traps.c:100 [inline]
 do_error_trap+0x12b/0x220 arch/x86/kernel/traps.c:197
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:216
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x1d1/0x1e0 lib/refcount.c:28
Code: e9 db fe ff ff 48 89 df e8 4c a4 18 fe e9 8a fe ff ff e8 82 8e d9 fd 48 c7 c7 00 e0 72 88 c6 05 2c 6c ec 06 01 e8 77 92 aa fd <0f> 0b e9 af fe ff ff 0f 1f 84 00 00 00 00 00 41 56 41 55 41 54 55
RSP: 0018:ffffc90007c97be8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815d5ba7 RDI: fffff52000f92f6f
RBP: 0000000000000003 R08: ffff888090f7c400 R09: ffffed1015cc45f2
R10: ffff8880ae622f8b R11: ffffed1015cc45f1 R12: ffff8880a37c4018
R13: ffff8880a415de00 R14: ffffc90007c97c90 R15: ffffc90007c97c90
 refcount_sub_and_test include/linux/refcount.h:274 [inline]
 refcount_dec_and_test include/linux/refcount.h:294 [inline]
 kref_put include/linux/kref.h:64 [inline]
 l2cap_chan_put+0x1d3/0x230 net/bluetooth/l2cap_core.c:502
 do_enable_set+0x4db/0x8e0 net/bluetooth/6lowpan.c:1083
 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268
 worker_thread+0x96/0xe20 kernel/workqueue.c:2414
 kthread+0x388/0x470 kernel/kthread.c:268
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351
Kernel Offset: disabled
Rebooting in 86400 seconds..