INFO: task syz-executor:5825 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:20176 pid:5825 tgid:5825 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5349 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7044 [inline] schedule+0x164/0x360 kernel/sched/core.c:7059 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7116 rwsem_down_write_slowpath+0x899/0x1040 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1bc/0x200 kernel/locking/rwsem.c:1591 __super_lock fs/super.c:58 [inline] __super_lock_excl fs/super.c:73 [inline] deactivate_super+0xa9/0xe0 fs/super.c:508 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 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:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f403c79d9d7 RSP: 002b:00007fffd2462828 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f403c832050 RCX: 00007f403c79d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffd24628e0 RBP: 00007fffd24628e0 R08: 00007fffd24638e0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffd2463970 R13: 00007f403c832050 R14: 000000000004b761 R15: 00007fffd24639b0 INFO: task syz.3.728:9116 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.728 state:D stack:26920 pid:9116 tgid:9108 ppid:5826 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5349 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7044 [inline] schedule+0x164/0x360 kernel/sched/core.c:7059 jfs_flush_journal+0x729/0xef0 fs/jfs/jfs_logmgr.c:1563 jfs_sync_fs+0x7d/0xa0 fs/jfs/super.c:649 dquot_quota_sync+0xda/0x4d0 fs/quota/dquot.c:758 __iterate_supers+0x13d/0x290 fs/super.c:927 quota_sync_all fs/quota/quota.c:69 [inline] __do_sys_quotactl fs/quota/quota.c:938 [inline] __se_sys_quotactl+0x3a7/0x9e0 fs/quota/quota.c:917 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: 0033:0x7fcb9879c799 RSP: 002b:00007fcb9965e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007fcb98a16090 RCX: 00007fcb9879c799 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101 RBP: 00007fcb98832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcb98a16128 R14: 00007fcb98a16090 R15: 00007fff4f2190b8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/48: 5 locks held by kworker/u8:4/62: #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085 #3: ffffffff9a4b0b70 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x83/0x580 lib/debugobjects.c:835 #4: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #4: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #4: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline] #4: ffffffff8e75f3a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0 arch/x86/kernel/unwind_orc.c:495 2 locks held by getty/5580: #0: ffff88823be860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by syz-executor/5825: #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 2 locks held by kworker/u8:11/6226: #0: ffff88801eff7148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x894/0x1780 kernel/workqueue.c:3261 #1: ffffc90003fafc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1780 kernel/workqueue.c:3262 1 lock held by syz-executor/8849: #0: ffffffff8e765638 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e765638 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.3.728/9116: #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.5.761/9262: #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880797300e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/9310: #0: ffff88805e0b40e0 (&type->s_umount_key#125){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805e0b40e0 (&type->s_umount_key#125){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88805e0b40e0 (&type->s_umount_key#125){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 2 locks held by syz.8.1148/11240: 1 lock held by syz.2.1167/11315: #0: ffffffff8e765500 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 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+0x1002/0x1060 kernel/hung_task.c:561 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8849 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 RIP: 0010:rcu_is_watching+0x70/0xb0 kernel/rcu/tree.c:754 Code: c3 98 59 1f 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 c9 62 72 11 74 11 83 e0 04 c1 e8 02 5b <41> 5e 41 5f c3 cc cc cc cc cc e8 71 fd 87 ff eb e8 48 c7 c7 80 58 RSP: 0018:ffffc900000077e8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff8297c138 RCX: 0000000000000102 RDX: 0000000000000000 RSI: ffffffff8c285ec0 RDI: ffffffff8c285e80 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90000007998 R11: ffffffff81b1cb00 R12: 0000000000000002 R13: ffffffff8e75f3a0 R14: ffffffff8e1ce790 R15: dffffc0000000000 FS: 0000555563fe2500(0000) GS:ffff88812543e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056183ec14218 CR3: 000000007aade000 CR4: 00000000003526f0 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x57/0x2e0 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6161 [inline] kfree+0x1c5/0x640 mm/slub.c:6479 free_kthread_struct+0xe6/0x150 kernel/kthread.c:137 free_task+0xe7/0x160 kernel/fork.c:559 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x870 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:739 irq_exit_rcu+0x9/0x30 kernel/softirq.c:756 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2039 [inline] RIP: 0010:vprintk_emit+0x45d/0x560 kernel/printk/printk.c:2478 Code: 0f 84 44 ff ff ff e8 e2 2a 21 00 fb eb 44 e8 da 2a 21 00 e8 25 b8 0d 0a 4d 85 f6 74 94 e8 cb 2a 21 00 fb 48 c7 c7 c0 17 75 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 3b 17 RSP: 0018:ffffc900045ef980 EFLAGS: 00000293 RAX: ffffffff81a57b45 RBX: ffffffff81a579bf RCX: ffff888037753d00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e7517c0 RBP: ffffc900045efa30 R08: ffffffff901245f7 R09: 1ffffffff20248be R10: dffffc0000000000 R11: fffffbfff20248bf R12: 0000000000000000 R13: 000000000000004c R14: 0000000000000200 R15: 1ffff920008bdf34 _printk+0xdd/0x130 kernel/printk/printk.c:2504 __ext4_msg+0x2b9/0x2d0 fs/ext4/super.c:995 ext4_put_super+0xb8/0xc40 fs/ext4/super.c:1300 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 kill_block_super+0x44/0x90 fs/super.c:1725 ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7459 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 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:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f93e339d9d7 Code: a2 c7 05 1c fd 24 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:00007ffe260d4af8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f93e3432050 RCX: 00007f93e339d9d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe260d4bb0 RBP: 00007ffe260d4bb0 R08: 00007ffe260d5bb0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe260d5c40 R13: 00007f93e3432050 R14: 000000000006e24e R15: 00007ffe260d5c80