INFO: task syz.5.472:7848 blocked for more than 143 seconds. Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.472 state:D stack:24424 pid:7848 tgid:7845 ppid:5838 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:148 f2fs_issue_checkpoint+0x376/0x570 fs/f2fs/checkpoint.c:-1 f2fs_do_sync_file+0x86a/0x1860 fs/f2fs/file.c:330 generic_write_sync include/linux/fs.h:3027 [inline] f2fs_file_write_iter+0x78e/0x2340 fs/f2fs/file.c:5203 do_iter_readv_writev+0x56e/0x7f0 fs/read_write.c:-1 vfs_writev+0x31a/0x960 fs/read_write.c:1057 do_pwritev fs/read_write.c:1153 [inline] __do_sys_pwritev2 fs/read_write.c:1211 [inline] __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202 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: 0033:0x7feab4d8e929 RSP: 002b:00007feab5be1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007feab4fb5fa0 RCX: 00007feab4d8e929 RDX: 0000000000000001 RSI: 00002000000001c0 RDI: 0000000000000005 RBP: 00007feab4e10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000e7b R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007feab4fb5fa0 R15: 00007ffddc6b84a8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 1 lock held by udevd/5199: #0: ffff8880b873b918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606 2 locks held by getty/5592: #0: ffff888030e350a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fee2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5837: #0: ffffffff8e144878 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #0: ffffffff8e144878 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 3 locks held by kworker/u8:17/6855: #0: ffff88801b6ff948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b6ff948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000435fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000435fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff888020ecc0e0 (&type->s_umount_key#105){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 1 lock held by syz.5.472/7848: #0: ffff888020ecc428 (sb_writers#25){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3092 [inline] #0: ffff888020ecc428 (sb_writers#25){.+.+}-{0:0}, at: vfs_writev+0x288/0x960 fs/read_write.c:1055 2 locks held by f2fs_ckpt-7:5/7859: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #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+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 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: 7859 Comm: f2fs_ckpt-7:5 Not tainted 6.16.0-rc1-syzkaller-00203-g4774cfe3543a #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:variable_test_bit arch/x86/include/asm/bitops.h:-1 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3823 [inline] RIP: 0010:validate_chain+0x4e/0x2140 kernel/locking/lockdep.c:3879 Code: 8b 46 20 89 c1 81 e1 00 80 04 00 81 f9 00 00 04 00 0f 85 61 02 00 00 41 89 d4 49 89 f6 25 ff 1f 00 00 48 0f a3 05 32 2b 06 12 <48> 89 3c 24 72 36 83 3d 85 ba 09 18 00 75 2d 90 e8 6d 96 1f 03 85 RSP: 0018:ffffc90003a0f3b8 EFLAGS: 00000007 RAX: 0000000000000d2b RBX: 0000000000000002 RCX: 0000000000040000 RDX: 0000000000000000 RSI: ffff88801c7b2940 RDI: ffff88801c7b1e00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff82428095 R10: dffffc0000000000 R11: fffffbfff1f4211f R12: 0000000000000000 R13: ffff88801c7b28f0 R14: ffff88801c7b2940 R15: cb001e96e0827470 FS: 0000000000000000(0000) GS:ffff888125c52000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562dace27950 CR3: 000000007b071000 CR4: 0000000000350ef0 Call Trace: __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] inode_to_wb_and_lock_list fs/fs-writeback.c:366 [inline] writeback_single_inode+0x205/0x6a0 fs/fs-writeback.c:1805 sync_inode_metadata+0xb1/0x100 fs/fs-writeback.c:2883 f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1152 [inline] block_operations fs/f2fs/checkpoint.c:1263 [inline] f2fs_write_checkpoint+0xaf6/0x1de0 fs/f2fs/checkpoint.c:1638 __write_checkpoint_sync fs/f2fs/checkpoint.c:1756 [inline] __checkpoint_and_complete_reqs+0xd9/0x3b0 fs/f2fs/checkpoint.c:1775 issue_checkpoint_thread+0xd9/0x260 fs/f2fs/checkpoint.c:1806 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245