------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 10 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 10 Comm: kworker/u16:0 Not tainted 5.13.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: qrtr_ns_handler qrtr_ns_worker
RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Code: 09 31 ff 89 de e8 77 c1 a4 fd 84 db 0f 85 36 ff ff ff e8 5a b9 a4 fd 48 c7 c7 00 20 c2 89 c6 05 f7 7e e5 09 01 e8 54 6b 05 05 <0f> 0b e9 17 ff ff ff e8 3b b9 a4 fd 0f b6 1d dc 7e e5 09 31 ff 89
RSP: 0018:ffffc900003df9f8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888011bce280 RSI: ffffffff815c0e95 RDI: fffff5200007bf31
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff815bacce R11: 0000000000000000 R12: ffff8880123c3640
R13: ffff888022ddc400 R14: ffff88802c28e230 R15: ffff88802c28e234
FS:  0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000040c580 CR3: 00000000157a4000 CR4: 0000000000150ee0
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:202 [inline]
 qrtr_node_lookup net/qrtr/qrtr.c:398 [inline]
 qrtr_send_resume_tx net/qrtr/qrtr.c:995 [inline]
 qrtr_recvmsg+0x85a/0x990 net/qrtr/qrtr.c:1063
 sock_recvmsg_nosec net/socket.c:888 [inline]
 sock_recvmsg net/socket.c:906 [inline]
 sock_recvmsg net/socket.c:902 [inline]
 kernel_recvmsg+0x110/0x160 net/socket.c:931
 qrtr_ns_worker+0x15a/0x1710 net/qrtr/ns.c:684
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294