------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 16442 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 16442 Comm: kworker/u4:7 Not tainted 5.14.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: qrtr_ns_handler qrtr_ns_worker RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25 Code: 09 31 ff 89 de e8 37 45 9f fd 84 db 0f 85 36 ff ff ff e8 ea 3e 9f fd 48 c7 c7 c0 75 e3 89 c6 05 35 a6 81 09 01 e8 41 a4 11 05 <0f> 0b e9 17 ff ff ff e8 cb 3e 9f fd 0f b6 1d 1a a6 81 09 31 ff 89 RSP: 0018:ffffc9000a59fa00 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888016560000 RSI: ffffffff815d89a5 RDI: fffff520014b3f32 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815d27de R11: 0000000000000000 R12: ffff888015bf0000 R13: ffff88814e5e0400 R14: ffff8880a05fca30 R15: ffff8880a05fca34 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000050e070 CR3: 0000000075c15000 CR4: 0000000000350ef0 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:999 [inline] qrtr_recvmsg+0x85a/0x990 net/qrtr/qrtr.c:1067 sock_recvmsg_nosec net/socket.c:943 [inline] sock_recvmsg net/socket.c:961 [inline] sock_recvmsg net/socket.c:957 [inline] kernel_recvmsg+0x110/0x160 net/socket.c:986 qrtr_ns_worker+0x15a/0x1720 net/qrtr/ns.c:684 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295