INFO: task syz.4.2156:20227 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2156 state:D stack:27176 pid:20227 tgid:20226 ppid:15864 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1304 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 fs/sync.c:111 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: 0033:0x7f1b5839bf79 RSP: 002b:00007f1b59297028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1b58615fa0 RCX: 00007f1b5839bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1b58615fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1b58616038 R14: 00007f1b58615fa0 R15: 00007ffeda001cd8 INFO: task syz.4.2156:20232 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.2156 state:D stack:27176 pid:20232 tgid:20226 ppid:15864 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1304 ksys_sync fs/sync.c:105 [inline] __ia32_sys_sync+0xc5/0x120 fs/sync.c:111 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: 0033:0x7f1b5839bf79 RSP: 002b:00007f1b59276028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f1b58616090 RCX: 00007f1b5839bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f1b58616090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1b58616128 R14: 00007f1b58616090 R15: 00007ffeda001cd8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by khungtaskd/30: #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5584: #0: ffff888035dfb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5874: #0: ffff88802746a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961 1 lock held by udevd/5888: 3 locks held by kworker/0:7/5937: 2 locks held by kworker/u8:29/19802: #0: ffff88801b0ac148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x855/0x1650 kernel/workqueue.c:3254 #1: ffffc9001039fc40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x87c/0x1650 kernel/workqueue.c:3255 1 lock held by syz.4.2156/20227: #0: ffff88802746a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304 1 lock held by syz.4.2156/20232: #0: ffff88802746a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1304 1 lock held by syz.5.2721/23294: 1 lock held by syz.2.2722/23301: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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:467 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: 5888 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:-1 [inline] RIP: 0010:debug_check_no_obj_freed+0x516/0x550 lib/debugobjects.c:1146 Code: 32 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 63 fe ff ff e8 be 2a 77 fd 48 ba 00 00 00 00 00 fc ff df e9 4f fe ff ff 4c 8b 74 24 30 <4c> 8b 7c 24 28 eb 02 31 db 48 8b 7c 24 10 48 8b 74 24 08 e8 f2 f0 RSP: 0018:ffffc90003a573f0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90003a57360 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200074ae6c R12: ffff88807d105000 R13: ffff88807d104000 R14: ffff88807d104000 R15: ffff88802b262268 FS: 00007fe9f35c4880(0000) GS:ffff888125460000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2dff0f CR3: 00000000572f2000 CR4: 00000000003526f0 Call Trace: __free_pages_prepare mm/page_alloc.c:1440 [inline] free_unref_folios+0x583/0x16d0 mm/page_alloc.c:3040 folios_put_refs+0x789/0x8d0 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x52c/0x1660 mm/shmem.c:1149 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+0x691/0xa70 fs/file_table.c:477 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:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [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: 0033:0x7fe9f2ea7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc5f05d420 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007fe9f35c4880 RCX: 00007fe9f2ea7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007fe9f35c46e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 0000561262b91190 R14: 0000000000000008 R15: 0000561262ba0f10