INFO: task kworker/u8:5:70 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:5 state:D stack:20416 pid:70 tgid:70 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 rxrpc_destroy_all_calls+0x44e/0x570 net/rxrpc/call_object.c:754 rxrpc_exit_net+0x6f/0xc0 net/rxrpc/net_ns.c:112 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252 cleanup_net+0x56e/0x800 net/core/net_namespace.c:702 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 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 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: pr[ 1361.258601][ T38] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: pr[ 1361.258601][ T38] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90000117c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90000117c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 4 locks held by kworker/u8:1/13: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:5/70: #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000155fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000155fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8f341560 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 2 locks held by getty/5357: #0: ffff8880371640a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5603: #0: ffff88806181a480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880401955b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #1: ffff8880401955b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #1: ffff8880401955b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline] #1: ffff8880401955b0 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5414 2 locks held by syz-executor/5607: 1 lock held by syz-executor/5611: #0: ffff88803d094480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 5 locks held by kworker/u8:11/9821: 2 locks held by kworker/u8:16/9823: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90005d47c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90005d47c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 7 locks held by kworker/u8:17/15191: 1 lock held by udevd/15226: #0: ffff888037e70480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 2 locks held by syz-executor/16545: #0: ffff888040ad0480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888061a65d28 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1074 [inline] #1: ffff888061a65d28 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2914 [inline] #1: ffff888061a65d28 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2938 [inline] #1: ffff888061a65d28 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5414 4 locks held by syz.5.4459/18429: 4 locks held by syz.3.4510/18573: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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+0xfd3/0x1030 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18573 Comm: syz.3.4510 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x80 kernel/kcov.c:210 Code: 89 fb e8 23 00 00 00 48 8b 3d f4 33 c6 0b 48 89 de 5b e9 83 f9 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d d8 23 a5 10 65 8b 35 f9 23 a5 RSP: 0018:ffffc9000e267378 EFLAGS: 00000202 RAX: ffffffff82329901 RBX: 8400000043e6c805 RCX: ffff88806011dc40 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005 RBP: ffffc9000e267601 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff9400021f361 R12: 8400000043e6c805 R13: dffffc0000000000 R14: 0000000000000005 R15: 8400000043e6c805 FS: 0000000000000000(0000) GS:ffff888126287000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff5b71bc8c CR3: 000000000ddb6000 CR4: 00000000003526f0 Call Trace: pte_pfn arch/x86/include/asm/pgtable.h:260 [inline] __page_table_check_pte_clear+0x43/0x70 mm/page_table_check.c:155 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] clear_full_ptes include/linux/pgtable.h:905 [inline] zap_present_folio_ptes mm/memory.c:1661 [inline] zap_present_ptes mm/memory.c:1730 [inline] do_zap_pte_range mm/memory.c:1832 [inline] zap_pte_range mm/memory.c:1934 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x337d/0x4860 mm/memory.c:2109 unmap_vmas+0x3ac/0x570 mm/memory.c:2178 exit_mmap+0x280/0x9e0 mm/mmap.c:1300 __mmput+0xcb/0x3d0 kernel/fork.c:1178 exit_mm+0x1f6/0x2d0 kernel/exit.c:582 do_exit+0x6a2/0x22c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119 get_signal+0x1284/0x1330 kernel/signal.c:3037 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98 __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: 0033:0x7f48ba51ce59 Code: Unable to access opcode bytes at 0x7f48ba51ce2f. RSP: 002b:00007f48b8755028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007f48ba796090 RCX: 00007f48ba51ce59 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007f48ba5b2d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f48ba796128 R14: 00007f48ba796090 R15: 00007ffc222f9888