INFO: task syz.0.6046:32580 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.6046 state:D stack:26296 pid:32580 tgid:32575 ppid:27798 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: 0033:0x7f953099c819 RSP: 002b:00007f9531785028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9530c16090 RCX: 00007f953099c819 RDX: 00000000000048d4 RSI: 0000200000001080 RDI: 0000000000000007 RBP: 00007f9530a32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9530c16128 R14: 00007f9530c16090 R15: 00007ffc860b3958 Showing all locks held in the system: 1 lock held by khungtaskd/30: #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 6 locks held by kworker/u8:11/3016: 1 lock held by dhcpcd/5491: 2 locks held by getty/5587: #0: ffff8880328480a0 (&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 1 lock held by syz.4.2856/17560: 4 locks held by kworker/u8:7/19181: #0: ffff88801bade948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801bade948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9001e3dfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9001e3dfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffffffff8fbbacf0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8e764800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 4 locks held by kworker/u8:12/19189: #0: ffff88801af7c948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801af7c948 ((wq_completion)ib-unreg-wq){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9001b957c40 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9001b957c40 ((work_completion)(&device->unregistration_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff8880408e8718 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x284/0x3f0 drivers/infiniband/core/device.c:1523 #3: ffff88801badd988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1717 1 lock held by syz.0.6046/32580: #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.8.6179/629: #0: ffffffff9a7b3b58 (nfnl_subsys_ipset){+.+.}-{4:4}, at: ip_set_nfnl_get_byindex+0x67/0x230 net/netfilter/ipset/ip_set_core.c:909 1 lock held by syz.6.6181/628: #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.2.6199/720: #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.3.6249/992: #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.5.6261/1080: #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-executor/1380: #0: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.1.6327/1671: #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.7.6355/1798: #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.9.6391/2022: #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.6.6490/2665: #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.2.6551/2977: #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.4.6677/3523: #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.5.6703/3640: #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 2 locks held by syz.8.6720/3706: #0: ffffffff8fbbacf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffff8880408e8718 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x39/0x300 drivers/infiniband/core/device.c:1675 2 locks held by syz-executor/3736: #0: ffffffff8fbbacf0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by dhcpcd/3763: #0: ffff888034c74260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888034c74260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3198 1 lock held by sed/3769: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 19189 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: ib-unreg-wq ib_unregister_work RIP: 0010:__lock_acquire+0x85e/0x2cf0 kernel/locking/lockdep.c:-1 Code: c1 c1 04 31 e9 01 d8 29 cb 89 ca c1 c2 06 31 da 01 c1 29 d0 89 d6 c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb 01 d6 29 da <89> dd c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 RSP: 0018:ffffc9001b957600 EFLAGS: 00000097 RAX: 000000005b2f1e17 RBX: 00000000991abecd RCX: 00000000c81e12a7 RDX: 00000000ef64ea2d RSI: 0000000034e9f9fe RDI: ffff88804ec00000 RBP: 00000000e1b2f174 R08: ffffffff826fb97e R09: ffff88801badda20 R10: dffffc0000000000 R11: ffffed100375bb37 R12: ffff88804ec00bf8 R13: ffff88804ec00bf8 R14: ffff88804ec00000 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888125555000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdad07da2fe CR3: 0000000079784000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 down_write+0x96/0x200 kernel/locking/rwsem.c:1590 __kernfs_remove+0x42e/0x660 fs/kernfs/dir.c:1524 kernfs_remove_by_name_ns+0xaf/0x130 fs/kernfs/dir.c:1722 kernfs_remove_by_name include/linux/kernfs.h:633 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xfc/0x2e0 fs/sysfs/group.c:328 sysfs_remove_groups+0x54/0xb0 fs/sysfs/group.c:352 destroy_gid_attrs drivers/infiniband/core/sysfs.c:1138 [inline] ib_free_port_attrs+0xc5/0x3b0 drivers/infiniband/core/sysfs.c:1362 remove_one_compat_dev drivers/infiniband/core/device.c:1010 [inline] remove_compat_devs drivers/infiniband/core/device.c:1022 [inline] disable_device+0x240/0x330 drivers/infiniband/core/device.c:1304 __ib_unregister_device+0x2cb/0x3f0 drivers/infiniband/core/device.c:1527 ib_unregister_work+0x19/0x30 drivers/infiniband/core/device.c:1639 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