Bluetooth: hci2: Opcode 0x0c1a failed: -4 Bluetooth: hci2: Opcode 0x0406 failed: -4 ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28, CPU#0: syz.6.759/7967 Modules linked in: CPU: 0 UID: 0 PID: 7967 Comm: syz.6.759 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 63400005 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 lr : refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 sp : ffff800093446d70 x29: ffff800093446d70 x28: 0000000000000000 x27: 1fffe00018ab08ea x26: dfff800000000000 x25: ffff0000c7370000 x24: 1fffe0001e37df8c x23: dfff800000000000 x22: ffff800082455418 x21: 0000000000000000 x20: ffff0000f1befc78 x19: ffff800089f06000 x18: 00000000ffffffff x17: ffff80008a0cdc80 x16: ffff80008a4f9958 x15: ffff0000c7370b50 x14: ffff0000c7370b30 x13: 0000000000000001 x12: 0000000000000000 x11: 000000000000140a x10: 0000000000ff0100 x9 : 3761c53b127e7b00 x8 : 3761c53b127e7b00 x7 : ffff8000804886d0 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000802f13b0 x2 : 0000000000000001 x1 : ffff0000c7370000 x0 : 0000000000000000 Call trace: refcount_warn_saturate+0x154/0x1f8 lib/refcount.c:28 (P) __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+0x368/0x38c lib/klist.c:206 klist_put+0xc0/0x118 lib/klist.c:217 klist_del lib/klist.c:230 [inline] klist_remove+0x118/0x264 lib/klist.c:249 device_move+0x164/0x5a8 drivers/base/core.c:4632 hci_conn_del_sysfs+0xb4/0x194 net/bluetooth/hci_sysfs.c:75 hci_conn_cleanup net/bluetooth/hci_conn.c:173 [inline] hci_conn_del+0x9bc/0xf04 net/bluetooth/hci_conn.c:1240 hci_conn_failed+0x224/0x334 net/bluetooth/hci_conn.c:1343 hci_abort_conn_sync+0x500/0x8e8 net/bluetooth/hci_sync.c:5763 hci_disconnect_all_sync+0x1b0/0x334 net/bluetooth/hci_sync.c:5786 hci_suspend_sync+0x324/0x88c net/bluetooth/hci_sync.c:6262 hci_suspend_dev+0x214/0x448 net/bluetooth/hci_core.c:2850 hci_suspend_notifier+0xe4/0x2b0 net/bluetooth/hci_core.c:2421 notifier_call_chain+0x194/0x60c kernel/notifier.c:85 notifier_call_chain_robust+0x54/0xc4 kernel/notifier.c:120 blocking_notifier_call_chain_robust+0x74/0xa8 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x34/0x60 kernel/power/main.c:172 snapshot_open+0x17c/0x268 kernel/power/user.c:77 misc_open+0x2d8/0x334 drivers/char/misc.c:163 chrdev_open+0x398/0x3e8 fs/char_dev.c:411 do_dentry_open+0x5c8/0x10dc fs/open.c:947 vfs_open+0x44/0x2d4 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2234/0x2a6c fs/namei.c:4858 do_file_open+0x1c4/0x2e4 fs/namei.c:4887 do_sys_openat2+0x114/0x1e8 fs/open.c:1364 do_sys_open+0xac/0xdc fs/open.c:1370 __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __arm64_sys_openat+0x9c/0xb8 fs/open.c:1381 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x25c arch/arm64/kernel/entry-common.c:723 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 irq event stamp: 5696 hardirqs last enabled at (5695): [] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:515 [inline] hardirqs last enabled at (5695): [] arm64_exit_to_kernel_mode+0x7c/0x90 arch/arm64/kernel/entry-common.c:62 hardirqs last disabled at (5696): [] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:412 softirqs last enabled at (5648): [] local_bh_enable+0x10/0x34 include/linux/bottom_half.h:32 softirqs last disabled at (5646): [] local_bh_disable+0x10/0x34 include/linux/bottom_half.h:19 ---[ end trace 0000000000000000 ]--- Bluetooth: hci2: Opcode 0x0406 failed: -4 Bluetooth: hci1: Opcode 0x0c1a failed: -4 Bluetooth: hci1: Opcode 0x0406 failed: -4 Bluetooth: hci1: Opcode 0x0406 failed: -4 Bluetooth: hci3: Opcode 0x0c1a failed: -4 Bluetooth: hci3: Opcode 0x0406 failed: -4 Bluetooth: hci3: Opcode 0x0406 failed: -4