INFO: task syz-executor:20232 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:21704 pid:20232 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 io_schedule+0x80/0xd0 kernel/sched/core.c:9023 folio_wait_bit_common+0x714/0xfa0 mm/filemap.c:1329 __filemap_get_folio+0xbc/0xbb0 mm/filemap.c:1910 truncate_inode_pages_range+0x46b/0xfb0 mm/truncate.c:401 evict+0x4dd/0x8d0 fs/inode.c:707 dispose_list fs/inode.c:738 [inline] evict_inodes+0x468/0x6a0 fs/inode.c:786 generic_shutdown_super+0x97/0x2b0 fs/super.c:672 kill_block_super+0x44/0x90 fs/super.c:1660 deactivate_locked_super+0x97/0x100 fs/super.c:481 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc883f9d897 RSP: 002b:00007ffe8f544148 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fc884031ef0 RCX: 00007fc883f9d897 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe8f544200 RBP: 00007ffe8f544200 R08: 00007ffe8f545200 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8f545290 R13: 00007fc884031ef0 R14: 00000000002ab3db R15: 00007ffe8f5452d0 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5536: #0: ffff88802d9df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 3 locks held by kworker/u4:5/15565: 1 lock held by syz-executor/19225: 9 locks held by syz-executor/19287: 1 lock held by syz-executor/20232: #0: ffff88802c7fe0e0 (&type->s_umount_key#110){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff88802c7fe0e0 (&type->s_umount_key#110){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff88802c7fe0e0 (&type->s_umount_key#110){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513 1 lock held by syz.7.3355/22887: #0: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #0: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by udevadm/22926: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13390 Comm: kworker/0:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events free_obj_work RIP: 0010:preempt_latency_start kernel/sched/core.c:5829 [inline] RIP: 0010:preempt_count_add+0xb9/0x1a0 kernel/sched/core.c:5852 Code: 0c 00 85 c0 74 09 31 db 31 ff e8 12 e4 0c 00 65 4c 8b 35 ca 37 a7 7e 49 81 c6 c8 14 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 2d c7 82 00 49 89 1e 5b 41 5e 41 5f c3 89 fb e8 RSP: 0018:ffffc900113af558 EFLAGS: 00000246 RAX: 1ffff1100581b299 RBX: ffffffff813b36de RCX: ffffffff972c6400 RDX: ffff88802c0d8000 RSI: 0000000000000001 RDI: ffffffff813b36de RBP: 0000000000000001 R08: ffffc900113af710 R09: 0000000000000004 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900113af648 R13: dffffc0000000000 R14: ffff88802c0d94c8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005596e8fbe240 CR3: 000000007ac78000 CR4: 00000000003506f0 Call Trace: unwind_next_frame+0xbe/0x2970 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x270 mm/slub.c:3852 free_obj_work+0x436/0x5a0 lib/debugobjects.c:332 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 vkms_vblank_simulate: vblank timer overrun