------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 9 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted 5.12.0-rc8-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+0x13d/0x1a0 lib/refcount.c:25
Code: c7 c0 59 71 8a 31 c0 e8 71 05 55 fd 0f 0b eb a3 e8 e8 a2 88 fd c6 05 91 dd 0b 0a 01 48 c7 c7 20 5a 71 8a 31 c0 e8 53 05 55 fd <0f> 0b eb 85 e8 ca a2 88 fd c6 05 74 dd 0b 0a 01 48 c7 c7 80 5a 71
RSP: 0018:ffffc90000ce6e98 EFLAGS: 00010046
RAX: def1d05f71edbe00 RBX: 0000000000000002 RCX: ffff888011970000
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff8164f2f2 R09: ffffed10173a3f1c
R10: ffffed10173a3f1c R11: 0000000000000000 R12: ffff888023492098
R13: 00000000fffffffe R14: 0000000000000a02 R15: ffff888023492000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000544db8 CR3: 00000000595d3000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_add include/linux/refcount.h:201 [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+0xc3/0xd0 net/qrtr/qrtr.c:397
 qrtr_send_resume_tx net/qrtr/qrtr.c:1009 [inline]
 qrtr_recvmsg+0x501/0xc20 net/qrtr/qrtr.c:1077
 qrtr_ns_worker+0x2d2/0x5ca0 net/qrtr/ns.c:684
 process_one_work+0x833/0x10c0 kernel/workqueue.c:2275
 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294