INFO: task syz.0.2283:14770 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.0.2283 state:D stack:28880 pid:14770 tgid:14760 ppid:5857 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776 bdev_open+0xa2/0xe40 block/bdev.c:961 bdev_file_open_by_dev block/bdev.c:1075 [inline] bdev_file_open_by_dev+0x179/0x210 block/bdev.c:1050 setup_bdev_super+0x78/0x730 fs/super.c:1612 get_tree_bdev_flags+0x363/0x620 fs/super.c:1692 cramfs_get_tree fs/cramfs/inode.c:963 [inline] cramfs_get_tree+0x40/0x50 fs/cramfs/inode.c:953 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount fs/namespace.c:3839 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4159 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount fs/namespace.c:4338 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc66399c799 RSP: 002b:00007fc6647c2028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fc663c16180 RCX: 00007fc66399c799 RDX: 0000200000000340 RSI: 0000200000000040 RDI: 0000200000000240 RBP: 00007fc663a32bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000a00005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc663c16218 R14: 00007fc663c16180 R15: 00007fff63dcd888 Showing all locks held in the system: 2 locks held by rcu_exp_gp_kthr/18: #0: ffff8880b843b1a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:655 [inline] #0: ffff8880b843b1a0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:639 #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline] #1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2c11/0x6120 kernel/sched/core.c:6902 1 lock held by khungtaskd/30: #0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e93e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5568: #0: ffff888037d730a0 (&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+0x419/0x1500 drivers/tty/n_tty.c:2211 6 locks held by kworker/1:1/5847: 1 lock held by udevd/5867: #0: ffff888027d7c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961 3 locks held by kworker/0:5/5921: #0: ffff88813fe67548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc90003f8fd08 (key_gc_work){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffffffff8e7f4ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 3 locks held by kworker/u8:15/12426: #0: ffff88813fe9c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250 #1: ffffc9000420fd08 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251 #2: ffffffff90610c28 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:313 2 locks held by syz.0.2283/14770: #0: ffff888038b520e0 (&type->s_umount_key#74/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd20 fs/super.c:345 #1: ffff888027d7c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:961 1 lock held by syz.7.2773/16995: #0: ffffffff90610c28 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff90610c28 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 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: 5847 Comm: kworker/1:1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:get_current arch/x86/include/asm/current.h:23 [inline] RIP: 0010:write_comp_data+0x10/0x90 kernel/kcov.c:245 Code: 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 39 04 05 12 49 89 f8 49 89 f1 49 89 d2 <65> 48 8b 3d 10 04 05 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 RSP: 0018:ffffc90000a08b78 EFLAGS: 00000246 RAX: 0000000000000102 RBX: 000000002af31dc4 RCX: ffffffff8998580f RDX: 00004189374bc6a7 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 00004189374bc6a7 R08: 0000000000000006 R09: 0000000000000000 R10: 00004189374bc6a7 R11: 0000000000000000 R12: 00000000000003e8 R13: 0000000000000005 R14: 0000000000000000 R15: 00000000044b82fa FS: 0000000000000000(0000) GS:ffff888124445000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f07b42b3e9c CR3: 00000000a91b2000 CR4: 00000000003526f0 Call Trace: pie_calculate_probability+0x26f/0x940 net/sched/sch_pie.c:352 fq_pie_timer+0x21a/0x5a0 net/sched/sch_fq_pie.c:402 call_timer_fn+0x19a/0x670 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers+0x757/0xb30 kernel/time/timer.c:2373 __run_timer_base kernel/time/timer.c:2385 [inline] __run_timer_base kernel/time/timer.c:2377 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2394 run_timer_softirq+0x1a/0x50 kernel/time/timer.c:2404 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xef/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x553/0x6b0 kernel/printk/printk.c:2478 Code: 00 4d 85 ed 0f 85 1b 01 00 00 e8 68 10 21 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 36 0b 21 00 48 85 ed 0f 85 27 01 00 00 48 10 21 00 45 31 c9 41 b8 01 00 00 00 31 c9 48 8d 05 00 00 00 RSP: 0018:ffffc90003ab72b8 EFLAGS: 00000287 RAX: 0000000000076bf3 RBX: 0000000000000059 RCX: ffffc9001b14b000 RDX: 0000000000100000 RSI: ffffffff81e7a3d4 RDI: ffff88801f790000 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff92000756e59 R13: 0000000000000200 R14: ffff8880202ac980 R15: ffffc90003ab7480 dev_vprintk_emit+0x394/0x3e0 drivers/base/core.c:4913 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4924 __dev_printk+0xcb/0x100 drivers/base/core.c:4936 _dev_notice+0xef/0x130 drivers/base/core.c:4981 usb_parse_configuration drivers/usb/core/config.c:715 [inline] usb_get_configuration.cold+0x1298/0x17a2 drivers/usb/core/config.c:998 usb_enumerate_device drivers/usb/core/hub.c:2527 [inline] usb_new_device+0x580/0x7d0 drivers/usb/core/hub.c:2665 hub_port_connect drivers/usb/core/hub.c:5567 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245