------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 77 at lib/refcount.c:25 refcount_warn_saturate+0x13d/0x1a0 lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 77 Comm: kworker/u4:2 Not tainted 5.12.0-rc7-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 58 11 8a 31 c0 e8 b1 4c 73 fd 0f 0b eb a3 e8 48 68 a4 fd c6 05 bf 12 cd 09 01 48 c7 c7 20 59 11 8a 31 c0 e8 93 4c 73 fd <0f> 0b eb 85 e8 2a 68 a4 fd c6 05 a2 12 cd 09 01 48 c7 c7 80 59 11
RSP: 0018:ffffc9000104f9b8 EFLAGS: 00010046
RAX: cd01f3b8ac405a00 RBX: 0000000000000002 RCX: ffff888011a1d4c0
RDX: 0000000000000000 RSI: 0000000080000001 RDI: 0000000000000000
RBP: 0000000000000002 R08: ffffffff8160b932 R09: ffffed1017383f1c
R10: ffffed1017383f1c R11: 0000000000000000 R12: ffff888016b89c98
R13: 1ffff11004e8d67e R14: 0000000000000282 R15: ffff888016b89c00
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000239f708 CR3: 000000002916e000 CR4: 00000000001526f0
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+0x443/0xa80 net/qrtr/qrtr.c:1077
 qrtr_ns_worker+0x4a1f/0x5470 net/qrtr/ns.c:684
 process_one_work+0x789/0xfd0 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