------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 4478 at lib/refcount.c:25 refcount_warn_saturate+0x13a/0x1d0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 4478 Comm: kworker/u9:1 Not tainted 6.10.0-rc1-syzkaller-00267-gcc8ed4d0a848-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: hci0 hci_rx_work RIP: 0010:refcount_warn_saturate+0x13a/0x1d0 lib/refcount.c:25 Code: c0 cb 1e 8c e8 c7 ae b1 fc 90 0f 0b 90 90 eb b9 e8 1b 80 ef fc c6 05 9a 04 f0 0a 01 90 48 c7 c7 20 cc 1e 8c e8 a7 ae b1 fc 90 <0f> 0b 90 90 eb 99 e8 fb 7f ef fc c6 05 7b 04 f0 0a 01 90 48 c7 c7 RSP: 0018:ffffc9000d40f440 EFLAGS: 00010246 RAX: 8178418b52383400 RBX: ffff88807498d080 RCX: ffff88802fa51e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000002 R08: ffffffff815846c2 R09: 1ffff110172a519a R10: dffffc0000000000 R11: ffffed10172a519b R12: ffff88807498e4a0 R13: ffff88807498e000 R14: dffffc0000000000 R15: 1ffff1100e931c94 FS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbe77aafffc CR3: 000000000e132000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] sock_hold include/net/sock.h:774 [inline] l2cap_sock_recv_cb+0x53d/0x600 net/bluetooth/l2cap_sock.c:1509 l2cap_conless_channel net/bluetooth/l2cap_core.c:6780 [inline] l2cap_recv_frame+0x8b6d/0x10670 net/bluetooth/l2cap_core.c:6833 hci_acldata_packet net/bluetooth/hci_core.c:3842 [inline] hci_rx_work+0x50f/0xca0 net/bluetooth/hci_core.c:4079 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244