------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 2 PID: 9 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Modules linked in:
CPU: 2 PID: 9 Comm: kworker/u16:0 Not tainted 5.10.0-rc6-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 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 07 c8 b8 fd 84 db 0f 85 36 ff ff ff e8 ea cf b8 fd 48 c7 c7 40 f9 9c 89 c6 05 ff 8c 21 09 01 e8 f3 dc f5 04 <0f> 0b e9 17 ff ff ff e8 cb cf b8 fd 0f b6 1d e4 8c 21 09 31 ff 89
RSP: 0018:ffffc900003cf9f8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888010a50240 RSI: ffffffff8158c875 RDI: fffff52000079f31
RBP: 0000000000000002 R08: 0000000000000001 R09: ffff88802cc2011b
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888011199640
R13: ffff888016509c00 R14: ffff8880163475f0 R15: ffff8880163475f4
FS:  0000000000000000(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001695394 CR3: 000000006e2b7000 CR4: 0000000000350ee0
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:196 [inline]
 qrtr_node_lookup net/qrtr/qrtr.c:389 [inline]
 qrtr_send_resume_tx net/qrtr/qrtr.c:981 [inline]
 qrtr_recvmsg+0x845/0x970 net/qrtr/qrtr.c:1044
 sock_recvmsg_nosec net/socket.c:885 [inline]
 sock_recvmsg net/socket.c:903 [inline]
 sock_recvmsg net/socket.c:899 [inline]
 kernel_recvmsg+0x110/0x160 net/socket.c:928
 qrtr_ns_worker+0x15a/0x1740 net/qrtr/ns.c:692
 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296