INFO: task syz-executor:5929 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21560 pid:5929 tgid:5929 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x81/0xe0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317 __folio_lock mm/filemap.c:1675 [inline] folio_lock include/linux/pagemap.h:1133 [inline] __filemap_get_folio+0x167/0xa40 mm/filemap.c:1929 truncate_inode_pages_range+0x3cf/0xb90 mm/truncate.c:388 evict+0x517/0x9c0 fs/inode.c:812 dispose_list fs/inode.c:852 [inline] evict_inodes+0x64c/0x6d0 fs/inode.c:906 generic_shutdown_super+0x9a/0x2c0 fs/super.c:628 kill_block_super+0x44/0x90 fs/super.c:1723 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8e766401f7 RSP: 002b:00007fffbf4cc388 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f8e766c1d7d RCX: 00007f8e766401f7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffbf4cc440 RBP: 00007fffbf4cc440 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffbf4cd4d0 R13: 00007f8e766c1d7d R14: 000000000004a89e R15: 00007fffbf4cd510 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/39: #0: ffffffff8d3a9d40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d3a9d40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d3a9d40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:5/153: #0: ffff888019481938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019481938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90003a4fbc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003a4fbc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 2 locks held by kworker/u8:14/3564: 2 locks held by kworker/u8:15/3620: #0: ffff888019481938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019481938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000dcf7bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000dcf7bc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 1 lock held by udevd/5184: #0: ffff888019440e58 (&n->list_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #0: ffff888019440e58 (&n->list_lock){+.+.}-{3:3}, at: get_partial_node+0x3a/0x3a0 mm/slub.c:2904 2 locks held by getty/5571: #0: ffff88823bf6e8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5929: #0: ffff8880612b80d0 (&type->s_umount_key#117){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880612b80d0 (&type->s_umount_key#117){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880612b80d0 (&type->s_umount_key#117){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 2 locks held by udevd/6043: 1 lock held by udevd/6138: 2 locks held by udevd/6141: #0: ffff888010626488 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:500 #1: ffff888038ba6598 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1024 [inline] #1: ffff888038ba6598 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: do_unlinkat+0x1c7/0x570 fs/namei.c:4724 2 locks held by udevadm/11432: 4 locks held by syz.3.1841/11438: 1 lock held by syz.4.1845/11445: #0: ffff8880387d20d0 (&type->s_umount_key#60/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 3 locks held by syz.0.1847/11447: 1 lock held by syz.1.1839/11451: ============================================= 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 08/18/2025 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:preempt_count_add+0x11c/0x1a0 kernel/sched/core.c:5821 Code: 83 3d 5b 4e 28 0d 00 75 19 90 48 c7 c7 60 31 ca 8a 48 c7 c6 a0 31 ca 8a e8 e1 57 f3 ff 90 0f 0b 90 90 90 89 df e9 58 ff ff ff <48> c7 c1 40 e3 8a 98 80 e1 07 80 c1 03 38 c1 0f 8c fa fe ff ff 89 RSP: 0018:ffffc90000167870 EFLAGS: 00000202 RAX: 0000000000000004 RBX: 0000000000000899 RCX: 00000000068e771c RDX: 0000000000000898 RSI: 00000000000007b1 RDI: 0000000000000001 RBP: ffffffff98c427b0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8ab11b90 R12: 1ffffffff31884f6 R13: 00000000ffffffff R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888127025000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3401cff8 CR3: 0000000035926000 CR4: 00000000003526f0 Call Trace: delay_tsc+0x17/0xc0 arch/x86/lib/delay.c:68 udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x166/0x2f0 drivers/tty/serial/8250/8250_port.c:1990 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396 console_emit_next_record kernel/printk/printk.c:3118 [inline] console_flush_all+0x698/0xcd0 kernel/printk/printk.c:3226 __console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245