INFO: task syz.6.1598:11969 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1598 state:D stack:22760 pid:11969 tgid:11961 ppid:6390 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 disable_device+0x1c6/0x320 drivers/infiniband/core/device.c:1325 __ib_unregister_device+0x2cb/0x3f0 drivers/infiniband/core/device.c:1555 ib_unregister_device_and_put+0xb8/0xf0 drivers/infiniband/core/device.c:1620 nldev_dellink+0x2d1/0x320 drivers/infiniband/core/nldev.c:1827 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline] rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] rdma_nl_rcv+0x6ae/0x980 drivers/infiniband/core/netlink.c:259 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x830 net/socket.c:2630 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684 __sys_sendmsg net/socket.c:2716 [inline] __do_sys_sendmsg net/socket.c:2721 [inline] __se_sys_sendmsg net/socket.c:2719 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f85f298f6c9 RSP: 002b:00007f85f3861038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f85f2be6180 RCX: 00007f85f298f6c9 RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000011 RBP: 00007f85f2a11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f85f2be6218 R14: 00007f85f2be6180 R15: 00007ffd7bb9c518 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88801a069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801a069948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000127ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000127ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by khungtaskd/31: #0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d660 (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: ffff88802f406148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88802f406148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000ac7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000ac7ba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194 1 lock held by kworker/u8:3/50: #0: ffff8880b883a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 4 locks held by kworker/u8:4/65: #0: ffff88801aedf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801aedf148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000211fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000211fba0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:670 #3: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by getty/5585: #0: ffff88814cca10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz.6.1598/11969: #0: ffffffff99b68938 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline] #0: ffffffff99b68938 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline] #0: ffffffff99b68938 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x302/0x980 drivers/infiniband/core/netlink.c:259 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1551 2 locks held by syz.1.1625/12064: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.5.1756/12504: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.4.1789/12645: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.0.1802/12707: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.7.1828/12796: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.3.1929/13206: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.9.1940/13268: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.6.2059/13725: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.5.2247/14462: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.8.2287/14628: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.2.2428/15135: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.1.2621/15849: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.0.2656/15979: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.7.2730/16219: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 2 locks held by syz.4.2811/16528: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffff88806c93c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1703 1 lock held by syz.3.2864/16786: 1 lock held by syz.3.2864/16787: 1 lock held by syz.9.2875/16840: #0: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:837 2 locks held by syz.9.2875/16844: #0: ffffffff8f331fb0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: reg_reload_regdb+0x13f/0x480 net/wireless/reg.c:1095 2 locks held by syz.9.2875/16847: #0: ffffffff8f331fb0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17929 1 lock held by syz.9.2875/16849: #0: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150 net/core/dev_ioctl.c:864 2 locks held by syz.5.2877/16838: #0: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8df430f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8df430f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 2 locks held by syz.6.2878/16850: #0: ffffffff8f2bf0b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:577 #1: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8f2cc048 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2083 ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 1321 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:rcu_is_watching+0x70/0xb0 kernel/rcu/tree.c:753 Code: c3 d8 af 6f 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 8b 03 65 ff 0d 79 2f c8 10 74 11 83 e0 04 c1 e8 02 5b <41> 5e 41 5f e9 d7 a3 a3 09 cc e8 91 e7 8c ff eb e8 48 c7 c7 40 33 RSP: 0018:ffffc900000071a0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: cebd91af8e996c00 RDX: 0000000000000000 RSI: ffffffff8bbf0740 RDI: ffffffff8bbf0700 RBP: ffffffff81738d25 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000007388 R11: fffff52000000e7d R12: 0000000000000002 R13: ffffffff8df3d660 R14: ffffffff8d92fdd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888126138000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000bbb030 CR3: 0000000053692000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 __kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x19a/0x6d0 mm/slub.c:6837 skb_release_data+0x62d/0x7c0 net/core/skbuff.c:1091 skb_release_all net/core/skbuff.c:1166 [inline] __kfree_skb net/core/skbuff.c:1180 [inline] sk_skb_reason_drop+0x127/0x170 net/core/skbuff.c:1218 kfree_skb_reason include/linux/skbuff.h:1322 [inline] __netif_receive_skb_core+0x2b2c/0x3060 net/core/dev.c:6103 __netif_receive_skb_one_core net/core/dev.c:6127 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6242 process_backlog+0x622/0x1530 net/core/dev.c:6594 __napi_poll+0xae/0x320 net/core/dev.c:7658 napi_poll net/core/dev.c:7721 [inline] net_rx_action+0x672/0xe50 net/core/dev.c:7873 handle_softirqs+0x286/0x870 kernel/softirq.c:622 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline] __dev_queue_xmit+0x1bfb/0x3740 net/core/dev.c:4838 dev_queue_xmit include/linux/netdevice.h:3368 [inline] batadv_send_skb_packet+0x418/0x690 net/batman-adv/send.c:100 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:391 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:419 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x62f/0x7e0 net/batman-adv/bat_iv_ogm.c:1697 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245