Bluetooth: Can't register HCI device
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BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
BUG: KASAN: null-ptr-deref in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
BUG: KASAN: null-ptr-deref in __refcount_sub_and_test include/linux/refcount.h:389 [inline]
BUG: KASAN: null-ptr-deref in __refcount_dec_and_test include/linux/refcount.h:432 [inline]
BUG: KASAN: null-ptr-deref in refcount_dec_and_test include/linux/refcount.h:450 [inline]
BUG: KASAN: null-ptr-deref in skb_unref include/linux/skbuff.h:1292 [inline]
BUG: KASAN: null-ptr-deref in __sk_skb_reason_drop net/core/skbuff.c:1223 [inline]
BUG: KASAN: null-ptr-deref in sk_skb_reason_drop+0x3d/0x1b0 net/core/skbuff.c:1251
Write of size 4 at addr 0000000000000090 by task syz.9.8845/31363

CPU: 2 UID: 0 PID: 31363 Comm: syz.9.8845 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 kasan_report+0xdf/0x1e0 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:186 [inline]
 kasan_check_range+0x10f/0x1e0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:112 [inline]
 atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:400 [inline]
 __refcount_sub_and_test include/linux/refcount.h:389 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 skb_unref include/linux/skbuff.h:1292 [inline]
 __sk_skb_reason_drop net/core/skbuff.c:1223 [inline]
 sk_skb_reason_drop+0x3d/0x1b0 net/core/skbuff.c:1251
 kfree_skb_reason include/linux/skbuff.h:1322 [inline]
 kfree_skb include/linux/skbuff.h:1331 [inline]
 h4_close+0x7b/0x120 drivers/bluetooth/hci_h4.c:78
 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:695 [inline]
 hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:717 [inline]
 hci_uart_tty_ioctl+0xa83/0xc80 drivers/bluetooth/hci_ldisc.c:771
 tty_ioctl+0x1204/0x1690 drivers/tty/tty_io.c:2801
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f700499c819
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f700588f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7004c15fa0 RCX: 00007f700499c819
RDX: 0000000000000000 RSI: 00000000400455c8 RDI: 0000000000000004
RBP: 00007f700588f090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007f7004c16038 R14: 00007f7004c15fa0 R15: 00007ffeb33b2298
 </TASK>
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