INFO: task syz.0.162:6373 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.162 state:D stack:23600 pid:6373 tgid:6373 ppid:5597 task_flags:0x40044c flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5510 [inline][ 299.301638][ T39] __schedule+0x1709/0x5530 __schedule+0x1709/0x5530 kernel/sched/core.c:7231[ 299.301638][ T39] __schedule+0x1709/0x5530 __schedule_loop kernel/sched/core.c:7308 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7604 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 device_lock include/linux/device.h:1104 [inline] usbdev_release+0x7f/0x740 drivers/usb/core/devio.c:1099 __fput+0x42a/0xa80 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3024 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc62088e68e RSP: 002b:00007ffd7d16c188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 0000555572224500 RCX: 00007fc62088e68e RDX: 00007ffd7d16c1e0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fc620b57da0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000025348 R13: 00007fc620b5618c R14: 00000000000247c0 R15: 00007fc620b56180 Showing all locks held in the system: 12 locks held by ktimers/0/16: #0: ffffffff8e0592e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #2: ffff8880b86241a8 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #2: ffff8880b86241a8 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_lock_callback kernel/softirq.c:881 [inline] #2: ffff8880b86241a8 (tasklet_sync_callback.cb_lock){+...}-{3:3}, at: tasklet_action_common+0xc5/0x600 kernel/softirq.c:931 #3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] #3: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57 #4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #4: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: ieee80211_rx_napi+0xd1/0x3d0 net/mac80211/rx.c:5710 #5: ffffffff8e0592e0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163 #6: ffff888070eb1d10 (&local->rx_path_lock){+...}-{3:3}, at: complete_with_flags kernel/sched/completion.c:25 [inline] #6: ffff888070eb1d10 (&local->rx_path_lock){+...}-{3:3}, at: complete+0x28/0x1b0 kernel/sched/completion.c:52 #7: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:572 [inline] #7: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: try_to_wake_up+0x67/0x1430 kernel/sched/core.c:4292 #8: ffff8880b873b920 (&rq->__lock){-...}-{2:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #8: ffff8880b873b920 (&rq->__lock){-...}-{2:2}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #8: ffff8880b873b920 (&rq->__lock){-...}-{2:2}, at: class_rcu_constructor include/linux/rcupdate.h:1183 [inline] #8: ffff8880b873b920 (&rq->__lock){-...}-{2:2}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495 #9: ffff88801e7ac900 (&p->pi_lock){-...}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:572 [inline] #9: ffff88801e7ac900 (&p->pi_lock){-...}-{2:2}, at: try_to_wake_up+0x67/0x1430 kernel/sched/core.c:4292 #10: ffffffff8e1c3880 (rcu_read_lock_sched){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #10: ffffffff8e1c3880 (rcu_read_lock_sched){....}-{1:2}, at: rcu_read_lock_sched include/linux/rcupdate.h:938 [inline] #10: ffffffff8e1c3880 (rcu_read_lock_sched){....}-{1:2}, at: pfn_valid include/linux/mmzone.h:2266 [inline] #10: ffffffff8e1c3880 (rcu_read_lock_sched){....}-{1:2}, at: __virt_addr_valid+0x137/0x390 arch/x86/mm/physaddr.c:54 #11: ffff8880b873b920 (&rq->__lock){-...}-{2:2}, at: raw_spin_rq_lock_nested+0xb2/0x160 kernel/sched/core.c:675 6 locks held by kworker/1:1/37: #0: ffff88801af55138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801af55138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801af55138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90000ac7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90000ac7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90000ac7c60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffff88802a8e4210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802a8e4210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899 #3: ffff888038502210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff888038502210 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xe3/0x990 drivers/usb/core/hub.c:2336 #4: ffff8880367b71d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff8880367b71d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff8880367b71d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 #5: ffff88802aa65a90 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #5: ffff88802aa65a90 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #5: ffff88802aa65a90 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 1 lock held by khungtaskd/39: #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6821 3 locks held by kworker/u8:2/44: #0: ffff88813fe5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88813fe5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88813fe5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90000b67c60 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90000b67c60 ((linkwatch_work).work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90000b67c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffffffff8f5ac2f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by getty/5349: #0: ffff8880327e10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cd32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 1 lock held by syz.0.162/6373: #0: ffff88802a8e4210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff88802a8e4210 (&dev->mutex){....}-{4:4}, at: usbdev_release+0x7f/0x740 drivers/usb/core/devio.c:1099 1 lock held by syz.2.197/6505: #0: ffff88802a8e4210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #0: ffff88802a8e4210 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x151/0x790 drivers/usb/core/devio.c:1054 1 lock held by syz.1.540/8067: #0: ffff88803fe34b38 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #0: ffff88803fe34b38 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: do_lock_mount+0x2a4/0x970 fs/namespace.c:2773 5 locks held by syz.1.540/8069: #0: ffff888036e2e510 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494 #1: ffff88803fe31000 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline] #1: ffff88803fe31000 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3785 [inline] #1: ffff88803fe31000 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_renaming+0x148/0x410 fs/namei.c:3878 #2: ffff88803fe29bd8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline] #2: ffff88803fe29bd8 (&sb->s_type->i_mutex_key#10){++++}-{4:4}, at: lock_two_nondirectories+0xe7/0x180 fs/inode.c:1254 #3: ffff88803fe34b38 (&sb->s_type->i_mutex_key#10/4){+.+.}-{4:4}, at: vfs_rename+0x696/0xef0 fs/namei.c:6028 #4: ffff88803fe347c8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_trylock_xattr fs/ext4/xattr.h:164 [inline] #4: ffff88803fe347c8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_try_to_expand_extra_isize fs/ext4/inode.c:6526 [inline] #4: ffff88803fe347c8 (&ei->xattr_sem){++++}-{4:4}, at: __ext4_mark_inode_dirty+0x3d0/0x700 fs/ext4/inode.c:6607 1 lock held by syz.7.541/8068: #0: ffffffff8f5ac2f8 (rtnl_mutex){+.+.}-{4:4}, at: bpf_xdp_link_release+0x26/0x520 net/core/dev.c:10559 1 lock held by syz.4.544/8077: #0: ffffffff8f5ac2f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5ac2f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac2f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x41b/0x810 net/core/rtnetlink.c:3635 1 lock held by syz.5.547/8081: #0: ffff8880703e0098 (&ctx->uring_lock){+.+.}-{4:4}, at: __do_sys_io_uring_register io_uring/register.c:1039 [inline] #0: ffff8880703e0098 (&ctx->uring_lock){+.+.}-{4:4}, at: __se_sys_io_uring_register+0x221/0x1a20 io_uring/register.c:1017 2 locks held by syz.6.548/8087: #0: ffffffff8de0a0a8 (tasklist_lock){++++}-{3:3}, at: read_lock include/linux/rwlock_rt.h:38 [inline] #0: ffffffff8de0a0a8 (tasklist_lock){++++}-{3:3}, at: sched_core_share_pid+0x338/0x790 kernel/sched/core_sched.c:217 #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffffff8e1c37c0 (rcu_read_lock){....}-{1:3}, at: rt_read_lock+0x277/0x4b0 kernel/locking/spinlock_rt.c:251 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: eb 6f 02 c3 cc cc cc cc cc cc cc 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 d3 3c 26 00 fb f4 cc cf 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8de07ca0 EFLAGS: 00000242 RAX: 000000000017497f RBX: ffffffff81994540 RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d87e102 RDI: ffffffff8bca5e80 RBP: ffffffff8de07d78 R08: ffff8880b8633d5b R09: 1ffff110170c67ab R10: dffffc0000000000 R11: ffffed10170c67ac R12: 0000000000000000 R13: 1ffffffff1bdedf0 R14: 1ffffffff1bc0f9c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125c49000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000044c0 CR3: 0000000077244000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 rest_init+0x378/0x3a0 init/main.c:723 start_kernel+0x392/0x3e0 init/main.c:1181 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x137/0x1b0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x157