------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 196 at lib/refcount.c:25 refcount_warn_saturate+0x120/0x190 lib/refcount.c:25 Modules linked in: CPU: 0 PID: 196 Comm: kworker/u4:5 Not tainted 5.13.0-rc7-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+0x120/0x190 lib/refcount.c:25 Code: 1d 9e fe f1 07 80 fb 01 0f 87 e0 25 17 04 83 e3 01 0f 85 5d ff ff ff 48 c7 c7 20 d2 78 88 c6 05 7e fe f1 07 01 e8 b6 44 06 04 <0f> 0b e9 43 ff ff ff 0f b6 1d 68 fe f1 07 80 fb 01 0f 87 d5 25 17 RSP: 0018:ffffc90000b57a30 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000004 RDI: fffff5200016af38 RBP: 0000000000000002 R08: 0000000000000001 R09: ffff8881f622095b R10: ffffed103ec4412b R11: 746e756f63666572 R12: ffff8881220be474 R13: ffff8881220be470 R14: 0000000000000282 R15: ffff88812c138000 FS: 0000000000000000(0000) GS:ffff8881f6200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000533198 CR3: 00000001183ca004 CR4: 00000000001706f0 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+0x75a/0x850 net/qrtr/qrtr.c:1063 qrtr_ns_worker+0x14c/0x1260 net/qrtr/ns.c:684 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276 worker_thread+0x598/0xf80 kernel/workqueue.c:2422 kthread+0x36f/0x450 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 irq event stamp: 3911390 hardirqs last enabled at (3911389): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (3911389): [] _raw_spin_unlock_irqrestore+0x40/0x90 kernel/locking/spinlock.c:191 hardirqs last disabled at (3911390): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (3911390): [] _raw_spin_lock_irqsave+0xa9/0xd0 kernel/locking/spinlock.c:159 softirqs last enabled at (3911386): [] lock_sock_nested+0x81/0xf0 net/core/sock.c:3068 softirqs last disabled at (3911384): [] spin_lock_bh include/linux/spinlock.h:359 [inline] softirqs last disabled at (3911384): [] lock_sock_nested+0x39/0xf0 net/core/sock.c:3065 ---[ end trace 35cc74d6fce09f45 ]---