------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 180 at lib/refcount.c:25 refcount_warn_saturate+0x120/0x190 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 180 Comm: kworker/u4:4 Not tainted 5.12.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
RIP: 0010:refcount_warn_saturate+0x120/0x190 lib/refcount.c:25
Code: 1d 71 ee d5 07 80 fb 01 0f 87 01 46 12 04 83 e3 01 0f 85 5d ff ff ff 48 c7 c7 40 08 58 88 c6 05 51 ee d5 07 01 e8 03 89 01 04 <0f> 0b e9 43 ff ff ff 0f b6 1d 3b ee d5 07 80 fb 01 0f 87 f6 45 12
RSP: 0000:ffffc90000427a30 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000004 RDI: fffff52000084f38
RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8881f632095b
R10: ffffed103ec6412b R11: 746e756f63666572 R12: ffff88811bf21934
R13: ffff88811bf21930 R14: 0000000000000286 R15: ffff88810b85a800
FS:  0000000000000000(0000) GS:ffff8881f6300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd68aa058e3 CR3: 000000010ee89002 CR4: 00000000001706e0
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]
 kref_get include/linux/kref.h:45 [inline]
 qrtr_node_acquire net/qrtr/qrtr.c:201 [inline]
 qrtr_node_lookup net/qrtr/qrtr.c:394 [inline]
 qrtr_send_resume_tx net/qrtr/qrtr.c:1004 [inline]
 qrtr_recvmsg+0x74b/0x840 net/qrtr/qrtr.c:1067
 qrtr_ns_worker+0x14c/0x1260 net/qrtr/ns.c:684
 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2275
 worker_thread+0x598/0xf80 kernel/workqueue.c:2421
 kthread+0x36f/0x450 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294