INFO: task syz.1.557:9831 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.557 state:D stack:27048 pid:9831 tgid:9828 ppid:8980 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379 rwsem_down_read_slowpath+0x6ba/0x920 kernel/locking/rwsem.c:1114 __down_read_common kernel/locking/rwsem.c:1291 [inline] __down_read kernel/locking/rwsem.c:1304 [inline] down_read+0x9c/0x330 kernel/locking/rwsem.c:1576 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 user_get_super+0xc8/0x120 fs/super.c:941 quotactl_block fs/quota/quota.c:889 [inline] __do_sys_quotactl fs/quota/quota.c:955 [inline] __se_sys_quotactl+0x538/0x9a0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f03cd19ce59 RSP: 002b:00007f03cb3f6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007f03cd415fa0 RCX: 00007f03cd19ce59 RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000801 RBP: 00007f03cd232e6f R08: 0000000000000000 R09: 0000000000000000 R10: 00002000000002c0 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f03cd416038 R14: 00007f03cd415fa0 R15: 00007ffce09654d8 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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:162 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 12533 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:752 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 1c a9 88 00 48 c7 c3 d8 08 3e 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d 69 c3 91 11 74 11 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc900071274d8 EFLAGS: 00000016 RAX: 0000000000000000 RBX: ffff8880b87338d8 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8c295400 RDI: ffffffff8c2953c0 RBP: ffffffff84c1da1b R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff206357f R12: 0000000000000000 R13: ffffffff9a71c938 R14: ffffffff8e28f7d8 R15: dffffc0000000000 FS: 0000555575063500(0000) GS:ffff888125353000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555773a1a78 CR3: 000000007bc39000 CR4: 0000000000350ef0 Call Trace: trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 __debug_check_no_obj_freed lib/debugobjects.c:1143 [inline] debug_check_no_obj_freed+0xcb/0x450 lib/debugobjects.c:1184 slab_free_hook mm/slub.c:2631 [inline] slab_free mm/slub.c:6310 [inline] kmem_cache_free+0xfd/0x650 mm/slub.c:6437 f2fs_destroy_node_manager+0x363/0xd80 fs/f2fs/node.c:3467 f2fs_put_super+0xc5a/0x1450 fs/f2fs/super.c:2071 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647 kill_block_super+0x44/0x90 fs/super.c:1665 kill_f2fs_super+0x3eb/0x700 fs/f2fs/super.c:5534 deactivate_locked_super+0xbc/0x130 fs/super.c:477 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6bf659e097 Code: a2 c7 05 5c 06 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffd8b86bef8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f6bf66322ca RCX: 00007f6bf659e097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd8b86bfb0 RBP: 00007ffd8b86bfb0 R08: 00007ffd8b86cfb0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd8b86d040 R13: 00007f6bf66322ca R14: 00000000000635d2 R15: 00007ffd8b86d080