INFO: task syz.4.2711:15892 blocked for more than 143 seconds. Not tainted 6.16.0-rc2-syzkaller-00278-g3f75bfff44be #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2711 state:D stack:28728 pid:15892 tgid:15888 ppid:5820 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:700 blk_trace_ioctl+0x19b/0x430 kernel/trace/blktrace.c:742 blkdev_common_ioctl+0xdce/0x2450 block/ioctl.c:629 blkdev_ioctl+0x4ef/0x6d0 block/ioctl.c:698 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fabaa58e929 RSP: 002b:00007fabab4aa038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fabaa7b6080 RCX: 00007fabaa58e929 RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000004 RBP: 00007fabaa610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fabaa7b6080 R15: 00007ffd34e02988 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by udevd/5188: 2 locks held by getty/5581: #0: ffff88814c3950a0 (&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 6 locks held by kworker/1:6/5931: #0: ffff888020e83548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888020e83548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000536fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000536fbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888028c33198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff888028c33198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5863 #3: ffff888028c36510 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3220 [inline] #3: ffff888028c36510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5432 [inline] #3: ffff888028c36510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] #3: ffff888028c36510 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] #3: ffff888028c36510 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21a3/0x4a00 drivers/usb/core/hub.c:5917 #4: ffff888028bb6868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5433 [inline] ffff888028bb6868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5675 [inline] ffff888028bb6868 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5835 [inline] ffff888028bb6868 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21cb/0x4a00 drivers/usb/core/hub.c:5917 #5: ffffffff8edc9830 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x163/0x1750 drivers/usb/core/hub.c:3035 3 locks held by kworker/0:0/11694: #0: ffff888020e83548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888020e83548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90014cafbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90014cafbc0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888028f2b198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #2: ffff888028f2b198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a00 drivers/usb/core/hub.c:5863 2 locks held by kworker/u8:7/13738: 3 locks held by syz.4.2711/15889: 1 lock held by syz.4.2711/15892: #0: ffff8880253474b8 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0xa3/0x640 kernel/trace/blktrace.c:700 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller-00278-g3f75bfff44be #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 15889 Comm: syz.4.2711 Not tainted 6.16.0-rc2-syzkaller-00278-g3f75bfff44be #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline] RIP: 0010:__pvclock_clocksource_read arch/x86/kernel/pvclock.c:77 [inline] RIP: 0010:pvclock_clocksource_read_nowd+0x42/0xf0 arch/x86/kernel/pvclock.c:120 Code: 56 44 89 f1 48 d3 e0 83 e5 fe 4c 89 3c 24 48 f7 24 24 48 0f ac d0 20 48 8b 4f 10 0f b6 57 1d 8b 37 39 f5 89 f5 74 70 0f 01 f9 <66> 90 48 89 c1 48 89 d0 48 c1 e0 20 48 09 c8 48 2b 47 08 44 8b 7f RSP: 0018:ffffc90000a08988 EFLAGS: 00000082 RAX: 000000003c661a58 RBX: ffff88807da530a0 RCX: 0000000000000001 RDX: 0000000000000294 RSI: ffffffff8db5aaa7 RDI: ffffffff92a00040 RBP: 000000000000000c R08: 0000000000000000 R09: ffffffff819c4965 R10: ffff88807931c810 R11: ffffed100f263905 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc90000a08a40 R15: 1ffff92000141144 FS: 00007fabab4cb6c0(0000) GS:ffff888125d83000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2cefeff8 CR3: 000000002bb9c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvm_sched_clock_read+0x11/0x20 arch/x86/kernel/kvmclock.c:91 sched_clock+0x17/0x60 arch/x86/kernel/tsc.c:288 sched_clock_cpu+0x74/0x430 kernel/sched/clock.c:394 cpu_clock include/linux/sched/clock.h:93 [inline] psi_group_change+0x20d/0x1210 kernel/sched/psi.c:793 psi_task_change+0xe5/0x250 kernel/sched/psi.c:912 psi_enqueue kernel/sched/stats.h:166 [inline] enqueue_task+0x345/0x420 kernel/sched/core.c:2086 activate_task kernel/sched/core.c:2126 [inline] ttwu_do_activate+0x1ee/0x8b0 kernel/sched/core.c:3746 ttwu_queue kernel/sched/core.c:4014 [inline] try_to_wake_up+0x745/0x1290 kernel/sched/core.c:4342 hrtimer_wakeup+0x4e/0x60 kernel/time/hrtimer.c:1997 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 2b 9e fb 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000e56f870 EFLAGS: 00000206 RAX: 77483e5285f8a900 RBX: 0000000000000000 RCX: 77483e5285f8a900 RDX: 0000000000000000 RSI: ffffffff8db5aaa7 RDI: ffffffff8be1b7c0 RBP: ffffffff822cc27a R08: 0000000000000000 R09: ffffffff822cc27a R10: dffffc0000000000 R11: ffffed1006b00f74 R12: 0000000000000002 R13: ffffffff8e13eda0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] __page_table_check_zero+0xd7/0x530 mm/page_table_check.c:138 page_table_check_free include/linux/page_table_check.h:43 [inline] free_pages_prepare mm/page_alloc.c:1249 [inline] __free_frozen_pages+0xc78/0xe60 mm/page_alloc.c:2706 relay_destroy_buf+0x10e/0x3a0 kernel/relay.c:201 relay_remove_buf kernel/relay.c:221 [inline] kref_put include/linux/kref.h:65 [inline] relay_close_buf kernel/relay.c:429 [inline] relay_open+0x734/0x920 kernel/relay.c:525 do_blk_trace_setup+0x591/0x9d0 kernel/trace/blktrace.c:590 blk_trace_setup+0x116/0x1f0 kernel/trace/blktrace.c:632 blk_trace_ioctl+0x181/0x430 kernel/trace/blktrace.c:730 blkdev_ioctl+0x416/0x6d0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fabaa58e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fabab4cb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fabaa7b5fa0 RCX: 00007fabaa58e929 RDX: 0000200000000240 RSI: 00000000c0481273 RDI: 0000000000000004 RBP: 00007fabaa610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fabaa7b5fa0 R15: 00007ffd34e02988