------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 259 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 259 Comm: kworker/u4:6 Not tainted 5.9.0-rc6-next-20200922-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+0x169/0x1e0 lib/refcount.c:25
Code: 07 31 ff 89 de e8 07 65 b9 fd 84 db 0f 85 36 ff ff ff e8 da 68 b9 fd 48 c7 c7 60 fa f8 88 c6 05 a8 2e ed 07 01 e8 d2 79 59 04 <0f> 0b e9 17 ff ff ff e8 bb 68 b9 fd 0f b6 1d 8d 2e ed 07 31 ff 89
RSP: 0018:ffffc90001bc79f8 EFLAGS: 00010086
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8880a92d02c0 RSI: ffffffff815e0415 RDI: fffff52000378f31
RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8880ae520f8b
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a91e5640
R13: ffff8880a5d2cc00 R14: ffff88809e9ad5b0 R15: ffff88809e9ad5b4
FS:  0000000000000000(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd2a9d8780 CR3: 0000000094b26000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __refcount_add include/linux/refcount.h:215 [inline]
 __refcount_inc include/linux/refcount.h:262 [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/0x1430 net/qrtr/ns.c:624
 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296