INFO: task syz-executor:10510 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-executor state:D stack:22416 pid:10510 tgid:10510 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 wb_wait_for_completion+0x3b2/0x700 fs/fs-writeback.c:227 sync_inodes_sb+0x224/0xbf0 fs/fs-writeback.c:3030 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x77/0x2d0 fs/super.c:626 kill_block_super+0x44/0x90 fs/super.c:1665 xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2286 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: 0033:0x7f529599f097 RSP: 002b:00007ffcdda9ede8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f5295a332ca RCX: 00007f529599f097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcdda9eea0 RBP: 00007ffcdda9eea0 R08: 00007ffcdda9fea0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcdda9ff30 R13: 00007f5295a332ca R14: 000000000009a4be R15: 00007ffcdda9ff70 Showing all locks held in the system: 1 lock held by khungtaskd/32: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 7 locks held by kworker/u8:9/3270: 2 locks held by getty/5374: #0: ffff8880364e70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 5 locks held by kworker/u8:10/6192: 1 lock held by syz-executor/9253: 2 locks held by syz-executor/10510: #0: ffff88807bac00d8 (&type->s_umount_key#91){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88807bac00d8 (&type->s_umount_key#91){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff88807bac00d8 (&type->s_umount_key#91){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:509 #1: ffff8880269e0870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline] ffff8880269e0870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x208/0xbf0 fs/fs-writeback.c:3028 2 locks held by iou-sqp-13684/13703: 3 locks held by syz.4.1723/13706: 2 locks held by syz.5.1726/13692: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 32 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13692 Comm: syz.5.1726 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1 Code: 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 c5 0a 00 00 48 0f bf 03 49 01 c0 49 8d 56 40 4c 89 f7 4c 89 c6 e8 33 0e 00 00 <84> c0 0f 84 4e 01 00 00 48 bb 00 00 00 00 00 fc ff df 48 8b 44 24 RSP: 0018:ffffc90000007740 EFLAGS: 00000082 RAX: 1ffff92000000f01 RBX: ffffffff90f35122 RCX: 0000000000000001 RDX: ffffc90000007828 RSI: dffffc0000000000 RDI: ffffc90000007d70 RBP: 1ffffffff21e6a24 R08: ffffc90000007d70 R09: ffffc90000007838 R10: dffffc0000000000 R11: fffff52000000f09 R12: dffffc0000000000 R13: ffffffff90f35123 R14: ffffc900000077e8 R15: ffffc90000007830 FS: 00007f259cb196c0(0000) GS:ffff888124f59000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdc90fed2f8 CR3: 000000001f766000 CR4: 0000000000350ef0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2226 __queue_work+0xcd8/0x10a0 kernel/workqueue.c:2401 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1794 [inline] __run_timers kernel/time/timer.c:2374 [inline] __run_timer_base+0x67e/0x8b0 kernel/time/timer.c:2386 run_timer_base kernel/time/timer.c:2395 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405 handle_softirqs+0x225/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 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 12 6b 21 00 fb eb 44 e8 0a 6b 21 00 e8 e5 9d 29 0a 4d 85 f6 74 94 e8 fb 6a 21 00 fb 48 c7 c7 a0 bf b4 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 fb 1b RSP: 0018:ffffc90014ccf540 EFLAGS: 00000246 RAX: ffffffff81a50745 RBX: ffffffff81a505bf RCX: 0000000000080000 RDX: ffffc9001aade000 RSI: 000000000007ffff RDI: ffffffff8eb4bfa0 RBP: ffffc90014ccf5f0 R08: ffffffff90576ff7 R09: 1ffffffff20aedfe R10: dffffc0000000000 R11: fffffbfff20aedff R12: 0000000000000000 R13: 0000000000000050 R14: 0000000000000200 R15: 1ffff92002999eac _printk+0xdd/0x130 kernel/printk/printk.c:2504 hugetlb_show_meminfo_node+0x175/0x320 mm/hugetlb.c:4571 show_free_areas mm/show_mem.c:397 [inline] __show_mem+0x1f74/0x21d0 mm/show_mem.c:411 warn_alloc_show_mem+0xd7/0x110 mm/page_alloc.c:3998 warn_alloc+0x258/0x270 mm/page_alloc.c:4024 __vmalloc_node_range_noprof+0x12c/0x1730 mm/vmalloc.c:4019 __vmalloc_node_noprof mm/vmalloc.c:4143 [inline] vmalloc_noprof+0xb2/0xe0 mm/vmalloc.c:4178 dvb_dmxdev_set_buffer_size+0xbe/0x1f0 drivers/media/dvb-core/dmxdev.c:337 dvb_demux_do_ioctl+0x45d/0x540 drivers/media/dvb-core/dmxdev.c:1101 dvb_usercopy+0x199/0x2e0 drivers/media/dvb-core/dvbdev.c:996 dvb_demux_ioctl+0x29/0x40 drivers/media/dvb-core/dmxdev.c:1201 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 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: 0033:0x7f259bb9de59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f259cb19028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f259be25fa0 RCX: 00007f259bb9de59 RDX: ffffffffff60014a RSI: 0000000000006f2d RDI: 000000000000000c RBP: 00007f259bc33e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f259be26038 R14: 00007f259be25fa0 R15: 00007fffd549d4c8