INFO: task syz-executor:6290 blocked for more than 143 seconds. Not tainted 6.16.0-rc3-syzkaller-00346-gafa9a6f4f574 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21160 pid:6290 tgid:6290 ppid:1 task_flags:0x40054c flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216 sync_inodes_sb+0x1bb/0xa10 fs/fs-writeback.c:2833 sync_filesystem+0x17a/0x230 fs/sync.c:64 generic_shutdown_super+0x6f/0x2c0 fs/super.c:622 kill_block_super+0x44/0x90 fs/super.c:1755 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x22e0 kernel/exit.c:964 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe0fb18df07 RSP: 002b:00007ffd71394c98 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffd9 RBX: 0000000000000065 RCX: 00007fe0fb18df07 RDX: 0000000000000200 RSI: 00007ffd71395e40 RDI: 00000000ffffff9c RBP: 00007fe0fb210925 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000207 R12: 00007ffd71395e40 R13: 00007fe0fb210925 R14: 000055555e48b4a8 R15: 00007ffd71398000 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 5 locks held by kworker/u8:3/49: #0: ffff88801b2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b2f6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc90000b97bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000b97bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f502bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800 net/core/net_namespace.c:662 #3: ffffffff8f50f7c8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12630 #4: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #4: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998 3 locks held by kworker/u8:6/987: #0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a481148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc900038cfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900038cfbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffffffff8f50f7c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5583: #0: ffff888034e0a0a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/6290: #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff888142bc87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff888142bc87d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831 1 lock held by syz-executor/6310: #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 2 locks held by kworker/u8:10/6793: #0: ffff88801decc148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801decc148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000b75fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b75fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 2 locks held by segctord/7053: 1 lock held by syz.3.329/7832: #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.8.361/7963: #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88806efc40e0 (&type->s_umount_key#81){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz-executor/8064: #0: ffff88805347c0e0 (&type->s_umount_key#63){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88805347c0e0 (&type->s_umount_key#63){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88805347c0e0 (&type->s_umount_key#63){+.+.}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e144800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 2 locks held by syz-executor/8959: #0: ffffffff8fa13f98 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8fa13f98 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8fa13f98 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f50f7c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f50f7c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f50f7c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4054 4 locks held by dhcpcd-run-hook/9144: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc3-syzkaller-00346-gafa9a6f4f574 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 9147 Comm: dhcpcd-run-hook Not tainted 6.16.0-rc3-syzkaller-00346-gafa9a6f4f574 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:473 [inline] RIP: 0010:lock_acquire+0x130/0x360 kernel/locking/lockdep.c:5873 Code: 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 e8 e0 02 00 00 48 83 c4 28 48 c7 c7 41 ee b6 8d e8 50 f0 c8 09 ff ff ff ff 65 0f c1 05 63 1d ff 10 83 f8 01 0f 85 c9 00 00 00 RSP: 0018:ffffc900052776a8 EFLAGS: 00000082 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 6e66dacd10c22300 RDX: 0000000000000000 RSI: ffffffff8db6ee41 RDI: ffffffff8be28cc0 RBP: ffffffff8209dc22 R08: 0000000000000000 R09: ffffffff8209dc22 R10: dffffc0000000000 R11: fffffbfff1f4209f R12: 0000000000000000 R13: ffff88807d24d8b8 R14: 0000000000000001 R15: 0000000000000246 FS: 00007feed7211c80(0000) GS:ffff888125c50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feed7466286 CR3: 0000000048005000 CR4: 0000000000350ef0 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] pmd_lock include/linux/mm.h:3083 [inline] pmd_install mm/memory.c:415 [inline] __pte_alloc+0xa2/0x1a0 mm/memory.c:445 do_anonymous_page mm/memory.c:5039 [inline] do_pte_missing mm/memory.c:4249 [inline] handle_pte_fault mm/memory.c:6069 [inline] __handle_mm_fault+0x4b8a/0x5620 mm/memory.c:6212 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6381 faultin_page mm/gup.c:1186 [inline] __get_user_pages+0x1af4/0x30b0 mm/gup.c:1488 __get_user_pages_locked mm/gup.c:1754 [inline] get_user_pages_remote+0x2f9/0xaa0 mm/gup.c:2650 get_arg_page+0x104/0x330 fs/exec.c:160 copy_string_kernel+0x191/0x2a0 fs/exec.c:563 do_execveat_common+0x3c5/0x6a0 fs/exec.c:1826 do_execve fs/exec.c:1929 [inline] __do_sys_execve fs/exec.c:2005 [inline] __se_sys_execve fs/exec.c:2000 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2000 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feed73ac107 Code: 0f 00 64 c7 00 07 00 00 00 b8 ff ff ff ff c9 c3 0f 1f 00 48 8b 05 a9 ee 0f 00 48 8b 10 e9 01 00 00 00 90 b8 3b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d c1 ec 0f 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe93b75338 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055f27d54d078 RCX: 00007feed73ac107 RDX: 000055f27d54d0a0 RSI: 000055f27d54d078 RDI: 000055f27d54d130 RBP: 000055f27d54d130 R08: 00007ffe93b79e51 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 000055f27d54d0a0 R13: 00007feed7571e8b R14: 000055f27d54d0a0 R15: 0000000000000000