------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 20 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Modules linked in: CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events sco_sock_timeout RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Code: 09 31 ff 89 de e8 67 d1 9b fd 84 db 0f 85 36 ff ff ff e8 7a cd 9b fd 48 c7 c7 a0 11 05 8a c6 05 78 4d a2 09 01 e8 d4 44 29 05 <0f> 0b e9 17 ff ff ff e8 5b cd 9b fd 0f b6 1d 5d 4d a2 09 31 ff 89 RSP: 0018:ffffc90000da7ce0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880119c8000 RSI: ffffffff815eea08 RDI: fffff520001b4f8e RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff815e87ae R11: 0000000000000000 R12: ffff88806cd3cc08 R13: ffff88807597d080 R14: ffff888010db9f00 R15: ffff8880b9d39280 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe4552eb218 CR3: 000000002a8ee000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:199 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] sock_hold include/net/sock.h:712 [inline] sco_sock_timeout+0x216/0x290 net/bluetooth/sco.c:89 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295