Oops: general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077]
CPU: 0 UID: 0 PID: 10573 Comm: syz.4.873 Not tainted 6.15.0-rc5-syzkaller-00032-g0d8d44db295c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:580 [inline]
RIP: 0010:__mutex_lock+0x14f/0xb90 kernel/locking/mutex.c:746
Code: d0 7c 08 84 d2 0f 85 ab 07 00 00 8b 35 9a f9 47 0f 85 f6 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 93 07 00 00 48 3b 5b 60 0f 85 e0 01 00 00 bf 01
RSP: 0018:ffffc9000b44fa80 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000010 RCX: 1ffffffff35654bc
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000070
RBP: ffffc9000b44fbc0 R08: ffffffff8a75c137 R09: ffffed100fe908d0
R10: ffffc9000b44fbe0 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc9000b44fb00 R14: 0000000000000000 R15: 1ffff92001689f5a
FS:  00007f080db946c0(0000) GS:ffff8881249ec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31206ff8 CR3: 0000000069a6e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 hci_devcd_register+0x47/0x170 net/bluetooth/coredump.c:433
 force_devcd_write+0x16c/0x340 drivers/bluetooth/hci_vhci.c:346
 full_proxy_write+0x13c/0x200 fs/debugfs/file.c:398
 vfs_write+0x25c/0x1180 fs/read_write.c:682
 ksys_write+0x12a/0x240 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f080cd8e969
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f080db94038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f080cfb5fa0 RCX: 00007f080cd8e969
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f080ce10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f080cfb5fa0 R15: 00007ffdc9393668
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:580 [inline]
RIP: 0010:__mutex_lock+0x14f/0xb90 kernel/locking/mutex.c:746
Code: d0 7c 08 84 d2 0f 85 ab 07 00 00 8b 35 9a f9 47 0f 85 f6 75 29 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 60 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 93 07 00 00 48 3b 5b 60 0f 85 e0 01 00 00 bf 01
RSP: 0018:ffffc9000b44fa80 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000010 RCX: 1ffffffff35654bc
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000070
RBP: ffffc9000b44fbc0 R08: ffffffff8a75c137 R09: ffffed100fe908d0
R10: ffffc9000b44fbe0 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffc9000b44fb00 R14: 0000000000000000 R15: 1ffff92001689f5a
FS:  00007f080db946c0(0000) GS:ffff8881249ec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056272dc5f950 CR3: 0000000069a6e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	d0 7c 08 84          	sarb   -0x7c(%rax,%rcx,1)
   4:	d2 0f                	rorb   %cl,(%rdi)
   6:	85 ab 07 00 00 8b    	test   %ebp,-0x74fffff9(%rbx)
   c:	35 9a f9 47 0f       	xor    $0xf47f99a,%eax
  11:	85 f6                	test   %esi,%esi
  13:	75 29                	jne    0x3e
  15:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  1c:	fc ff df
  1f:	48 8d 7b 60          	lea    0x60(%rbx),%rdi
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 93 07 00 00    	jne    0x7c7
  34:	48 3b 5b 60          	cmp    0x60(%rbx),%rbx
  38:	0f 85 e0 01 00 00    	jne    0x21e
  3e:	bf                   	.byte 0xbf
  3f:	01                   	.byte 0x1