INFO: task syz.5.1174:10971 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1174 state:D stack:25240 pid:10971 tgid:10960 ppid:7678 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121 disable_device+0x16f/0x280 drivers/infiniband/core/device.c:1325 __ib_unregister_device+0x2b4/0x480 drivers/infiniband/core/device.c:1555 ib_unregister_device_and_put+0x5a/0x80 drivers/infiniband/core/device.c:1620 nldev_dellink+0x21f/0x320 drivers/infiniband/core/nldev.c:1827 rdma_nl_rcv_msg+0x38a/0x6e0 drivers/infiniband/core/netlink.c:195 rdma_nl_rcv_skb.constprop.0.isra.0+0x2d0/0x430 drivers/infiniband/core/netlink.c:239 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa5d/0xc30 net/socket.c:2592 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646 __sys_sendmsg+0x16d/0x220 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faff158f749 RSP: 002b:00007fafeeff2038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007faff17e6360 RCX: 00007faff158f749 RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 000000000000000a RBP: 00007faff1613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faff17e63f8 R14: 00007faff17e6360 R15: 00007fff9eedb7e8 Showing all locks held in the system: 1 lock held by rcu_tasks_trace/29: #0: ffffffff8e3c8a70 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0x72d/0xe20 kernel/rcu/tasks.h:614 1 lock held by khungtaskd/31: #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c9620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:14/4966: #0: ffff88801badc948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc9000f267c90 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffffffff9012b2d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xad/0x830 net/core/net_namespace.c:670 #3: ffff88804b06c700 (&device->unregistration_lock){+.+.}-{4:4}, at: rdma_dev_change_netns+0x30/0x320 drivers/infiniband/core/device.c:1703 2 locks held by getty/5572: #0: ffff88814e02d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5819: #0: ffffffff8e3d4d78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/1:8/5898: 6 locks held by kworker/0:9/5974: #0: ffff888142ab4948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232 #1: ffffc90003067c90 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233 #2: ffff88802a099198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88802a099198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x52f0 drivers/usb/core/hub.c:5899 #3: ffff88804c8a7198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff88804c8a7198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006 #4: ffff88801f796160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88801f796160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006 #5: ffffffff8e27be90 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xa9/0x250 kernel/umh.c:214 2 locks held by syz.5.1174/10971: #0: ffffffff9af7abd8 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg+0x169/0x6e0 drivers/infiniband/core/netlink.c:164 #1: ffff88804b06c700 (&device->unregistration_lock){+.+.}-{4:4}, at: __ib_unregister_device+0x23b/0x480 drivers/infiniband/core/device.c:1551 4 locks held by udevd/12340: #0: ffff8880696ef0a0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182 #1: ffff88805761bc88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888063fc6d28 (kn->active#19){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888063fc6d28 (kn->active#19){++++}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff888058d56198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff888058d56198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by syz.6.1720/13046: #0: ffffffff90141aa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff90141aa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:6964 1 lock held by syz.6.1720/13050: #0: ffffffff90141aa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff90141aa8 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x371/0xe90 net/core/rtnetlink.c:6964 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x133/0x180 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xe66/0x1180 kernel/hung_task.c:515 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: c6 5f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 49 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 00000000027a4371 RBX: 0000000000000000 RCX: ffffffff8b7816d9 RDX: 0000000000000000 RSI: ffffffff8dacde3b RDI: ffffffff8bf2b380 RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000 R13: ffffffff8e097b40 R14: ffffffff9088b3d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3f4a1f CR3: 000000007dc57000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffeff7ff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3ef/0x4d0 init/main.c:1206 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148