INFO: task syz.4.84:6451 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 >[ 308.388652][ T37] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.84 state:D stack:24128 pid:6451 tgid:6419 ppid:5797 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 f2fs_issue_checkpoint+0x3e7/0x790 fs/f2fs/checkpoint.c:-1 f2fs_do_sync_file+0x81b/0x1a20 fs/f2fs/file.c:354 generic_write_sync include/linux/fs.h:2640 [inline] f2fs_file_write_iter+0x74c/0x2550 fs/f2fs/file.c:5288 iter_file_splice_write+0x9a6/0x10f0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x104/0x160 fs/splice.c:1159 splice_direct_to_actor+0x545/0xc80 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x19b/0x2a0 fs/splice.c:1228 do_sendfile+0x547/0x7e0 fs/read_write.c:1372 __do_sys_sendfile64 fs/read_write.c:1433 [inline] __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6c75e7c819 RSP: 002b:00007f6c6bcb5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f6c760f6090 RCX: 00007f6c75e7c819 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004 RBP: 00007f6c75f12c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000020fffe82 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6c760f6128 R14: 00007f6c760f6090 R15: 00007fffd9623598 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/37: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:4/67: #0: ffff88801e6ce938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff88801e6ce938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc9000152fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc9000152fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888028d260d0 (&type->s_umount_key#68){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 2 locks held by getty/5557: #0: ffff8880286860a0 (&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+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/6214: 1 lock held by syz.4.84/6451: #0: ffff888028d26480 (sb_writers#18){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1158 3 locks held by f2fs_ckpt-7:4/6440: 2 locks held by syz.8.217/7437: #0: ffff888028d260d0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888028d260d0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff8880254f88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline] #1: ffff8880254f88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940 2 locks held by syz.8.217/7438: #0: ffff888028d260d0 (&type->s_umount_key#68){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888028d260d0 (&type->s_umount_key#68){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 #1: ffff8880254f88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline] #1: ffff8880254f88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x209/0xc30 fs/fs-writeback.c:2940 1 lock held by syz.2.321/8160: 1 lock held by syz.5.323/8167: 1 lock held by syz.9.326/8184: 5 locks held by syz.3.324/8204: 4 locks held by dhcpcd-run-hook/8205: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 8167 Comm: syz.5.323 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4868 [inline] RIP: 0010:__lock_acquire+0x451/0x2cf0 kernel/locking/lockdep.c:5187 Code: 0f b6 89 c5 00 00 00 84 c9 0f b6 d3 0f b6 c9 0f 44 ca 89 0c 24 45 8b a6 b0 0b 00 00 41 8d 4c 24 ff 83 f9 ff 41 bd ff ff ff ff <44> 0f 4c e9 41 ff c5 41 8d 5c 24 01 49 ff cc 89 d9 83 c1 fe 78 40 RSP: 0018:ffffc900058c7430 EFLAGS: 00000013 RAX: 000000000002000b RBX: 0000000000000003 RCX: 0000000000000001 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff888026084908 R08: ffffffff8b2681d0 R09: ffffffff8ddcb980 R10: 0000000000000000 R11: ffffed1009e83ab0 R12: 0000000000000002 R13: 00000000ffffffff R14: ffff888026083d00 R15: ffff8880260848b8 FS: 00007fc737a966c0(0000) GS:ffff888126432000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f54585dc000 CR3: 000000005bd5c000 CR4: 00000000003526f0 Call Trace: reacquire_held_locks+0x104/0x190 kernel/locking/lockdep.c:5385 __lock_release kernel/locking/lockdep.c:5574 [inline] lock_release+0x199/0x3d0 kernel/locking/lockdep.c:5889 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock_irq include/linux/spinlock_rt.h:122 [inline] filemap_remove_folio+0xee/0x200 mm/filemap.c:258 truncate_inode_folio+0x5d/0x70 mm/truncate.c:176 shmem_undo_range+0x42f/0x1660 mm/shmem.c:1145 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x240/0x9e0 mm/shmem.c:1407 evict+0x61e/0xb10 fs/inode.c:846 __dentry_kill+0x1a2/0x5e0 fs/dcache.c:670 finish_dput+0xc9/0x480 fs/dcache.c:879 __fput+0x6a3/0xa90 fs/file_table.c:477 fput_close_sync+0x11f/0x240 fs/file_table.c:574 __do_sys_close fs/open.c:1509 [inline] __se_sys_close fs/open.c:1494 [inline] __x64_sys_close+0x7e/0x110 fs/open.c:1494 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc7397fd04e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007fc737a95da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007fc737a966c0 RCX: 00007fc7397fd04e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006 RBP: 0000000000000010 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00007fc737a95ee0 R14: 00007fc737a95ea0 R15: 00007fc72f655000