Bluetooth: hci5: Opcode 0x0c1a failed: -4 Bluetooth: hci5: Error when powering off device on rfkill (-4) Bluetooth: hci1: Opcode 0x0c1a failed: -4 Bluetooth: hci1: Error when powering off device on rfkill (-4) ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: lib/refcount.c:28 at 0x0, CPU#0: syz.2.4523/21801 Modules linked in: CPU: 0 UID: 0 PID: 21801 Comm: syz.2.4523 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:refcount_warn_saturate+0xb2/0x110 lib/refcount.c:28 Code: 74 26 00 0b 67 48 0f b9 3a eb 4a e8 d8 d2 36 fd 48 8d 3d 71 26 00 0b 67 48 0f b9 3a eb 37 e8 c5 d2 36 fd 48 8d 3d 6e 26 00 0b <67> 48 0f b9 3a eb 24 e8 b2 d2 36 fd 48 8d 3d 6b 26 00 0b 67 48 0f RSP: 0018:ffffc900051477b8 EFLAGS: 00010283 RAX: ffffffff848a779b RBX: 0000000000000003 RCX: 0000000000080000 RDX: ffffc9000d1b9000 RSI: 0000000000043430 RDI: ffffffff8f8a9e10 RBP: 0000000000000000 R08: ffff888054da5b80 R09: 0000000000000005 R10: 0000000000000004 R11: 0000000000000002 R12: ffff8880303ed800 R13: ffff8880395e5060 R14: ffff8880395e5078 R15: dffffc0000000000 FS: 00007f196f95c6c0(0000) GS:ffff8881260b1000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fca347f5f98 CR3: 00000000377ac000 CR4: 00000000003526f0 Call Trace: __refcount_sub_and_test include/linux/refcount.h:400 [inline] __refcount_dec_and_test include/linux/refcount.h:432 [inline] refcount_dec_and_test include/linux/refcount.h:450 [inline] kref_put include/linux/kref.h:64 [inline] klist_dec_and_del+0x3c7/0x3d0 lib/klist.c:206 klist_put lib/klist.c:217 [inline] klist_del lib/klist.c:230 [inline] klist_remove+0x1bd/0x340 lib/klist.c:249 device_move+0x193/0x700 drivers/base/core.c:4615 hci_conn_del_sysfs+0xb8/0x170 net/bluetooth/hci_sysfs.c:75 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline] hci_conn_del+0xc36/0x11b0 net/bluetooth/hci_conn.c:1234 hci_conn_hash_flush+0x191/0x230 net/bluetooth/hci_conn.c:2638 hci_dev_close_sync+0x821/0xff0 net/bluetooth/hci_sync.c:5326 hci_dev_do_close+0x2f/0x90 net/bluetooth/hci_core.c:501 hci_rfkill_set_block+0x21d/0x2e0 net/bluetooth/hci_core.c:929 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346 rfkill_fop_write+0x44b/0x570 net/rfkill/core.c:1301 vfs_write+0x27e/0xb30 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f196eb8f749 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:00007f196f95c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f196ede5fa0 RCX: 00007f196eb8f749 RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000004 RBP: 00007f196ec13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f196ede6038 R14: 00007f196ede5fa0 R15: 00007ffd2feb66f8 ---------------- Code disassembly (best guess): 0: 74 26 je 0x28 2: 00 0b add %cl,(%rbx) 4: 67 48 0f b9 3a ud1 (%edx),%rdi 9: eb 4a jmp 0x55 b: e8 d8 d2 36 fd call 0xfd36d2e8 10: 48 8d 3d 71 26 00 0b lea 0xb002671(%rip),%rdi # 0xb002688 17: 67 48 0f b9 3a ud1 (%edx),%rdi 1c: eb 37 jmp 0x55 1e: e8 c5 d2 36 fd call 0xfd36d2e8 23: 48 8d 3d 6e 26 00 0b lea 0xb00266e(%rip),%rdi # 0xb002698 * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: eb 24 jmp 0x55 31: e8 b2 d2 36 fd call 0xfd36d2e8 36: 48 8d 3d 6b 26 00 0b lea 0xb00266b(%rip),%rdi # 0xb0026a8 3d: 67 addr32 3e: 48 rex.W 3f: 0f .byte 0xf