------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 136 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 Modules linked in: CPU: 0 PID: 136 Comm: kworker/u4:1 Not tainted 5.15.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Workqueue: qrtr_ns_handler qrtr_ns_worker pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 sp : ffff800018e66e40 x29: ffff800018e66e40 x28: dfff800000000000 x27: ffff7000031ccddc x26: ffff800018e66f00 x25: 0000000000000000 x24: 00000000003a6056 x23: ffff0000cc2ff670 x22: 0000000000000000 x21: 0000000000000002 x20: ffff0000ce43e098 x19: ffff800016dd0000 x18: 0000000000000002 x17: ff808000083386a0 x16: ffff800011a080c4 x15: ffff8000083386a0 x14: 00000000ffffffff x13: ffffffffffffffff x12: 0000000000000000 x11: ff80800008330148 x10: 0000000000000000 x9 : 88691575a4efc200 x8 : 88691575a4efc200 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff800018e665b8 x4 : ffff800014aa0700 x3 : ffff8000085518f8 x2 : 0000000000000001 x1 : 0000000100000001 x0 : 000000000000002a Call trace: refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25 __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+0xe0/0x110 net/qrtr/qrtr.c:398 qrtr_send_resume_tx net/qrtr/qrtr.c:1003 [inline] qrtr_recvmsg+0x3e0/0x958 net/qrtr/qrtr.c:1071 sock_recvmsg_nosec net/socket.c:947 [inline] sock_recvmsg net/socket.c:965 [inline] kernel_recvmsg+0x128/0x154 net/socket.c:990 qrtr_ns_worker+0x25c/0x4fb8 net/qrtr/ns.c:687 process_one_work+0x84c/0x14b8 kernel/workqueue.c:2306 worker_thread+0x910/0x1034 kernel/workqueue.c:2453 kthread+0x37c/0x45c kernel/kthread.c:319 ret_from_fork+0x10/0x20 :870 irq event stamp: 142944 hardirqs last enabled at (142943): [] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] hardirqs last enabled at (142943): [] _raw_spin_unlock_irqrestore+0xac/0x158 kernel/locking/spinlock.c:194 hardirqs last disabled at (142944): [] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] hardirqs last disabled at (142944): [] _raw_spin_lock_irqsave+0xfc/0x14c kernel/locking/spinlock.c:162 softirqs last enabled at (142940): [] spin_unlock_bh include/linux/spinlock.h:408 [inline] softirqs last enabled at (142940): [] lock_sock_nested+0x160/0x1ec net/core/sock.c:3223 softirqs last disabled at (142938): [] spin_lock_bh include/linux/spinlock.h:368 [inline] softirqs last disabled at (142938): [] lock_sock_nested+0x108/0x1ec net/core/sock.c:3219 ---[ end trace c5272773e48d5854 ]---