INFO: task syz.0.644:7907 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.0.644 state:D stack:28152 pid:7907 tgid:7906 ppid:5832 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 bdev_open+0xe0/0xd30 block/bdev.c:962 bdev_file_open_by_dev+0x1be/0x240 block/bdev.c:1076 setup_bdev_super+0x5a/0x5b0 fs/super.c:1609 nilfs_get_tree+0x3d7/0x870 fs/nilfs2/super.c:1226 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5eea38f749 RSP: 002b:00007f5eeb168038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f5eea5e5fa0 RCX: 00007f5eea38f749 RDX: 0000200000000540 RSI: 00002000000000c0 RDI: 0000200000000440 RBP: 00007f5eea413f91 R08: 00002000000001c0 R09: 0000000000000000 R10: 0000000000008084 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5eea5e6038 R14: 00007f5eea5e5fa0 R15: 00007ffe42f2e758 INFO: task syz.0.644:7914 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.0.644 state:D stack:28360 pid:7914 tgid:7906 ppid:5832 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 super_lock+0x1c8/0x3b0 fs/super.c:115 super_lock_excl fs/super.c:146 [inline] grab_super+0xad/0x350 fs/super.c:531 sget_fc+0x2c2/0xa40 fs/super.c:801 sget_dev+0xab/0xf0 fs/super.c:1405 nilfs_get_tree+0x196/0x870 fs/nilfs2/super.c:1221 vfs_get_tree+0x92/0x2a0 fs/super.c:1751 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3712 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5eea38f749 RSP: 002b:00007f5ee85f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f5eea5e6180 RCX: 00007f5eea38f749 RDX: 0000200000000540 RSI: 00002000000000c0 RDI: 0000200000000440 RBP: 00007f5eea413f91 R08: 00002000000001c0 R09: 0000000000000000 R10: 0000000000008084 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5eea5e6218 R14: 00007f5eea5e6180 R15: 00007ffe42f2e758 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e33f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:8/2116: 2 locks held by getty/5587: #0: ffff88814dbc90a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 2 locks held by syz.2.42/6066: 1 lock held by udevd/6225: #0: ffff88802600a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by syz.1.617/7798: 2 locks held by syz.0.644/7907: #0: ffff888048f660e0 (&type->s_umount_key#84/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xaa0 fs/super.c:344 #1: ffff88802600a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 1 lock held by syz.2.1260/10137: #0: ffffffff8e344d00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816 2 locks held by syz-executor/10392: #0: ffffffff8f71ef50 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e344e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956 ============================================= NMI backtrace for cpu 0 CPU: 0 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_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:160 [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:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6389 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:check_preemption_disabled+0x1/0x120 lib/smp_processor_id.c:13 Code: 80 47 e2 8b 48 c7 c6 c0 47 e2 8b eb 1c 66 66 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 55 <41> 57 41 56 53 48 83 ec 10 65 48 8b 05 be e1 5c 07 48 89 44 24 08 RSP: 0018:ffffc90018a878e0 EFLAGS: 00000287 RAX: 0000000000000001 RBX: ffff888077d7c5e0 RCX: 1ffff92003150f14 RDX: 0000000000000000 RSI: ffffffff8be247c0 RDI: ffffffff8be24780 RBP: ffff88814d3d1a00 R08: 0000000000000000 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52003150f20 R12: dffffc0000000000 R13: ffffffff86f54507 R14: ffff888077d7c5f8 R15: 00000000000000c0 FS: 0000000000000000(0000) GS:ffff888125adc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fd46f83000 CR3: 000000000e138000 CR4: 00000000003526f0 DR0: 0000000000000003 DR1: 00000000000001f8 DR2: 000000000000008e DR3: 000000000000057a DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3b0 kernel/locking/lockdep.c:5879 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_unlock_bh+0x1b/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline] nsim_dev_trap_report_work+0x7c7/0xb80 drivers/net/netdevsim/dev.c:922 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3443 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246