------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 54 at lib/refcount.c:25 refcount_warn_saturate+0xdd/0x140 lib/refcount.c:25
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 54 Comm: kworker/u4:2 Not tainted 5.7.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: qrtr_ns_handler qrtr_ns_worker
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x128/0x182 lib/dump_stack.c:118
 panic+0x22a/0x4e3 kernel/panic.c:221
 __warn.cold.10+0x25/0x26 kernel/panic.c:582
 report_bug+0x1ad/0x270 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:175 [inline]
 do_error_trap+0x123/0x210 arch/x86/kernel/traps.c:267
 do_invalid_op+0x31/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0xdd/0x140 lib/refcount.c:25
Code: f1 dc 6e 06 01 e8 6f 59 f2 fd 0f 0b eb 9d 80 3d e0 dc 6e 06 00 75 94 48 c7 c7 a0 89 ce 87 c6 05 d0 dc 6e 06 01 e8 4f 59 f2 fd <0f> 0b e9 7a ff ff ff 80 3d ba dc 6e 06 00 0f 85 6d ff ff ff 48 c7
RSP: 0018:ffffc90000f379a0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffff8880a8fb7c98 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000007 RDI: ffffffff8b8fe1a0
RBP: 0000000000000002 R08: ffffed1015d245f1 R09: ffffed1015d245f1
R10: ffff8880ae922f83 R11: ffffed1015d245f0 R12: ffff8880a8fb7c98
R13: ffff8880a42cedf4 R14: ffff8880a42cedf0 R15: 0000000050f32cd6
 refcount_add include/linux/refcount.h:204 [inline]
 refcount_inc include/linux/refcount.h:241 [inline]
 kref_get include/linux/kref.h:45 [inline]
 qrtr_node_acquire net/qrtr/qrtr.c:194 [inline]
 qrtr_node_lookup+0x7b/0x90 net/qrtr/qrtr.c:386
 qrtr_send_resume_tx net/qrtr/qrtr.c:972 [inline]
 qrtr_recvmsg+0x499/0x7f0 net/qrtr/qrtr.c:1035
 kernel_recvmsg+0xb1/0x140 net/socket.c:932
 qrtr_ns_worker+0x164/0x10d7 net/qrtr/ns.c:624
 process_one_work+0x908/0x15d0 kernel/workqueue.c:2268
 worker_thread+0x82/0xb50 kernel/workqueue.c:2414
 kthread+0x340/0x410 kernel/kthread.c:268
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..