syzbot

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000016: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7]
CPU: 1 UID: 0 PID: 25289 Comm: syz.0.4294 Tainted: G     U              6.16.0-syzkaller-11952-g6e64f4580381 #0 PREEMPT(full) 
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:577 [inline]
RIP: 0010:__mutex_lock+0x14d/0x10b0 kernel/locking/mutex.c:760
Code: 08 84 d2 0f 85 70 0b 00 00 44 8b 05 ed 7f 53 0f 45 85 c0 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 56 0b 00 00 48 3b 5b 60 0f 85 e7 01 00 00 bf 01
RSP: 0018:ffffc9000b8b7a70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000050 RCX: 1ffffffff35c9610
RDX: 0000000000000016 RSI: ffffffff8de23cbd RDI: 00000000000000b0
RBP: ffffc9000b8b7bc0 R08: 0000000000000000 R09: ffffed100cf6f5b0
R10: ffffc9000b8b7be0 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 1ffff92001716f5a R15: ffffffff8a994037
FS:  00007f50d08036c0(0000) GS:ffff8881247cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d9feff8 CR3: 0000000060e04000 CR4: 00000000003526f0
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+0x12e/0x1a0 fs/debugfs/file.c:388
 vfs_write+0x29d/0x1150 fs/read_write.c:684
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f50cf98ebe9
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:00007f50d0803038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f50cfbb6180 RCX: 00007f50cf98ebe9
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f50cfa11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f50cfbb6218 R14: 00007f50cfbb6180 R15: 00007ffff5122028
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:577 [inline]
RIP: 0010:__mutex_lock+0x14d/0x10b0 kernel/locking/mutex.c:760
Code: 08 84 d2 0f 85 70 0b 00 00 44 8b 05 ed 7f 53 0f 45 85 c0 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 56 0b 00 00 48 3b 5b 60 0f 85 e7 01 00 00 bf 01
RSP: 0018:ffffc9000b8b7a70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000050 RCX: 1ffffffff35c9610
RDX: 0000000000000016 RSI: ffffffff8de23cbd RDI: 00000000000000b0
RBP: ffffc9000b8b7bc0 R08: 0000000000000000 R09: ffffed100cf6f5b0
R10: ffffc9000b8b7be0 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 1ffff92001716f5a R15: ffffffff8a994037
FS:  00007f50d08036c0(0000) GS:ffff8881247cc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000fe000 CR3: 0000000060e04000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	08 84 d2 0f 85 70 0b 	or     %al,0xb70850f(%rdx,%rdx,8)
   7:	00 00                	add    %al,(%rax)
   9:	44 8b 05 ed 7f 53 0f 	mov    0xf537fed(%rip),%r8d        # 0xf537ffd
  10:	45 85 c0             	test   %r8d,%r8d
  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 56 0b 00 00    	jne    0xb8a
  34:	48 3b 5b 60          	cmp    0x60(%rbx),%rbx
  38:	0f 85 e7 01 00 00    	jne    0x225
  3e:	bf                   	.byte 0xbf
  3f:	01                   	.byte 0x1