------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 5840 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28 Modules linked in: CPU: 1 UID: 0 PID: 5840 Comm: syz-executor Not tainted 6.13.0-rc3-syzkaller-00691-gae418e95dd93 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28 Code: e0 69 5f 8c e8 97 de 9d fc 90 0f 0b 90 90 eb 99 e8 cb 3a dd fc c6 05 ed 2a 42 0b 01 90 48 c7 c7 40 6a 5f 8c e8 77 de 9d fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 a8 3a dd fc c6 05 c7 2a 42 0b 01 90 RSP: 0018:ffffc90003f5f7b8 EFLAGS: 00010246 RAX: 8192385edc568400 RBX: ffff88807af18878 RCX: ffff88805f668000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff81601a42 R09: fffffbfff1cfa210 R10: dffffc0000000000 R11: fffffbfff1cfa210 R12: ffff88807af18860 R13: ffffffff86037620 R14: 1ffff1100f5e310c R15: ffff88807af18860 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efde842ce80 CR3: 000000000e736000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:275 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [inline] kref_put include/linux/kref.h:64 [inline] klist_dec_and_del+0x3ec/0x3f0 lib/klist.c:206 klist_put lib/klist.c:217 [inline] klist_del lib/klist.c:230 [inline] klist_remove+0x25e/0x480 lib/klist.c:249 device_move+0x1b4/0x710 drivers/base/core.c:4636 hci_conn_del_sysfs+0xac/0x160 net/bluetooth/hci_sysfs.c:75 hci_conn_cleanup net/bluetooth/hci_conn.c:174 [inline] hci_conn_del+0x8c4/0xc40 net/bluetooth/hci_conn.c:1164 hci_conn_hash_flush+0x258/0x350 net/bluetooth/hci_conn.c:2699 hci_dev_close_sync+0xa42/0x11c0 net/bluetooth/hci_sync.c:5212 hci_dev_do_close net/bluetooth/hci_core.c:482 [inline] hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2697 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664 __fput+0x23c/0xa50 fs/file_table.c:450 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0e2b985d29 Code: Unable to access opcode bytes at 0x7f0e2b985cff. RSP: 002b:00007fffde6e4e98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0e2b985d29 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043 RBP: 00007f0e2ba03003 R08: 00007fffde6e2c36 R09: 0000000000024a21 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000020 R13: 0000000000024a21 R14: 00007fffde6e5040 R15: 0000000000000106