INFO: task syz.1.2223:17006 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.2223 state:D stack:26424 pid:17006 tgid:17001 ppid:13323 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfnl_lock net/netfilter/nfnetlink.c:96 [inline] nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c0/0x27b0 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:721 [inline] __sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2585 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2639 __sys_sendmsg net/socket.c:2671 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2674 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0aa9f9c799 RSP: 002b:00007f0aaaed7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0aaa216090 RCX: 00007f0aa9f9c799 RDX: 0000000004000084 RSI: 0000200000000000 RDI: 000000000000000e RBP: 00007f0aaa032c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0aaa216128 R14: 00007f0aaa216090 R15: 00007ffe6cac0b68 INFO: task syz.8.2244:17081 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.2244 state:D stack:26040 pid:17081 tgid:17078 ppid:15048 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfnl_lock net/netfilter/nfnetlink.c:96 [inline] nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c0/0x27b0 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:721 [inline] __sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2585 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2639 __sys_sendmsg net/socket.c:2671 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2674 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4082b9c799 RSP: 002b:00007f4080df6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4082e15fa0 RCX: 00007f4082b9c799 RDX: 00000000000000c0 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f4082c32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4082e16038 R14: 00007f4082e15fa0 R15: 00007fffbea086c8 INFO: task syz.4.2270:17180 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2270 state:D stack:24512 pid:17180 tgid:17179 ppid:13509 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfnl_lock net/netfilter/nfnetlink.c:96 [inline] nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 nfnetlink_rcv+0x2c0/0x27b0 net/netfilter/nfnetlink.c:667 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:721 [inline] __sock_sendmsg net/socket.c:736 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2585 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2639 __sys_sendmsg net/socket.c:2671 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2674 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d8c39c799 RSP: 002b:00007f0d8d2dd028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0d8c615fa0 RCX: 00007f0d8c39c799 RDX: 0000000000000090 RSI: 00002000000002c0 RDI: 000000000000000a RBP: 00007f0d8c432c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0d8c616038 R14: 00007f0d8c615fa0 R15: 00007ffc7a509748 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: #0: ffff8880313d7948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff8880313d7948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000ac7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000ac7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4198 3 locks held by kworker/u8:3/48: #0: ffff88813fe54148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88813fe54148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90000b87c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90000b87c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8fbc9608 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by klogd/5185: #0: ffff8880b873ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 2 locks held by getty/5582: #0: ffff8880349030a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz.0.318/7271: 1 lock held by syz.1.2223/17006: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.8.2244/17081: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.4.2270/17180: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.5.2357/17663: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.0.2374/17792: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.2.2459/18201: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.7.2461/18209: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.6.2478/18359: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.6.2478/18362: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.9.2503/18582: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 3 locks held by syz-executor/18802: #0: ffff888034ef4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff888034ef4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff888034ef40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346 #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644 1 lock held by syz.1.2555/19059: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.8.2612/19387: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.3.2624/19456: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.4.2637/19558: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.4.2637/19561: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 1 lock held by syz.0.2654/19699: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline] #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0xa6e/0x12c0 net/netfilter/nfnetlink.c:293 3 locks held by syz-executor/19785: #0: ffff88814c024ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff88814c024ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff88814c0240c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346 #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644 5 locks held by syz-executor/19916: #0: ffff88808a464ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff88808a464ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff88808a4640c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346 #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644 #3: ffff88804d98db00 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x92/0x570 net/bluetooth/l2cap_core.c:1777 #4: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #4: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 3 locks held by syz.7.2700/19984: #0: ffff8880713e4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff8880713e4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff8880713e40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346 #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644 3 locks held by syz.2.2704/19996: #0: ffff88814dc7cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline] #0: ffff88814dc7cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716 #1: ffff88814dc7c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346 #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline] #2: ffffffff8fd55a88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 48 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:rcu_preempt_read_enter kernel/rcu/tree_plugin.h:391 [inline] RIP: 0010:__rcu_read_lock+0x14/0x60 kernel/rcu/tree_plugin.h:414 Code: 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 53 65 48 8b 1d bb 39 71 11 48 81 c3 c4 04 00 00 <48> 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 RSP: 0018:ffffc90000b87448 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffff88801e6aa344 RCX: 0000000080000001 RDX: ffffc90000b87618 RSI: dffffc0000000000 RDI: ffffc90000b87588 RBP: dffffc0000000000 R08: ffffc90000b87578 R09: 0000000000000000 R10: ffffc90000b875d8 R11: fffff52000170ebd R12: 1ffff92000170eb1 R13: ffffc90000b875c0 R14: ffffc90000b87588 R15: ffffc90000b87588 FS: 0000000000000000(0000) GS:ffff888125455000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560372f92168 CR3: 0000000075792000 CR4: 00000000003526f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:848 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0x9e/0x23c0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5260 [inline] __kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5368 kmalloc_reserve net/core/skbuff.c:635 [inline] __alloc_skb+0x2c1/0x7d0 net/core/skbuff.c:713 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245