INFO: task kworker/u8:3:11386 blocked for[ 1330.021041][ T38] INFO: task kworker/u8:3:11386 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:23224 pid:11386 tgid:11386 ppid:2 task_flags:0x4208160 flags:0x00080000 Workqueue: netns cleanup_net Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 rxrpc_destroy_all_calls+0x564/0x660 net/rxrpc/call_object.c:757 rxrpc_exit_net+0x6f/0xc0 net/rxrpc/net_ns.c:112 ops_exit_list net/core/net_namespace.c:199 [inline] ops_undo_list+0x49a/0x990 net/core/net_namespace.c:252 cleanup_net+0x4de/0x7b0 net/core/net_namespace.c:696 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5556: #0: ffff88814d8670a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:3/11386: #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900139d7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900139d7bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8e898720 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670 1 lock held by syz.6.23748/23411: 1 lock held by syz.4.23758/23426: #0: ffff8880898183b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:353 [inline] #0: ffff8880898183b0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x214/0x4d0 mm/util.c:579 4 locks held by syz.4.23758/23429: 1 lock held by syz.0.23768/23448: #0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: write_lock_irq include/linux/rwlock_rt.h:104 [inline] #0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: exit_notify kernel/exit.c:742 [inline] #0: ffffffff8d20c0a8 (tasklist_lock){++++}-{3:3}, at: do_exit+0x712/0x22f0 kernel/exit.c:983 3 locks held by syz.0.23768/23449: 2 locks held by syz.1.23769/23450: ============================================= NMI backtrace for cpu 1 CPU: 1 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 10/25/2025 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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 23429 Comm: syz.4.23758 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_static_branch include/trace/events/preemptirq.h:36 [inline] RIP: 0010:trace_irq_disable+0x2/0x100 include/trace/events/preemptirq.h:36 Code: 28 b0 ec 0f 01 00 00 00 48 8b 3c 24 eb 1a 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 56 <53> 66 90 65 8b 05 a8 99 eb 0f 83 f8 08 73 33 89 c3 c1 e8 06 48 8d RSP: 0018:ffffc9000484f3b8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8ce0bb44 RDI: ffffffff8ad5124a RBP: ffffc9000484f498 R08: ffffffff82300e88 R09: ffff888070649bd8 R10: dffffc0000000000 R11: fffffbfff1db668f R12: 1ffff92000909e85 R13: dffffc0000000000 R14: ffff888070649b80 R15: ffffc9000484f420 FS: 00007fa2f94de6c0(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000f88 CR3: 0000000065cd0000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline] _raw_spin_lock_irqsave+0x1a/0x60 kernel/locking/spinlock.c:162 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x14a/0x3e0 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:44 [inline] inode_add_bytes+0x38/0x140 fs/stat.c:931 __dquot_alloc_space+0x285/0xea0 fs/quota/dquot.c:1698 dquot_alloc_space_nodirty include/linux/quotaops.h:299 [inline] dquot_alloc_block_nodirty include/linux/quotaops.h:326 [inline] shmem_inode_acct_blocks+0x2a2/0x460 mm/shmem.c:242 shmem_alloc_and_add_folio mm/shmem.c:1962 [inline] shmem_get_folio_gfp+0x8f0/0x1a70 mm/shmem.c:2556 shmem_fault+0x170/0x380 mm/shmem.c:2757 __do_fault+0x138/0x390 mm/memory.c:5320 do_read_fault mm/memory.c:5755 [inline] do_fault mm/memory.c:5889 [inline] do_pte_missing+0x18ca/0x27a0 mm/memory.c:4401 handle_pte_fault mm/memory.c:6273 [inline] __handle_mm_fault mm/memory.c:6411 [inline] handle_mm_fault+0xcc1/0x1330 mm/memory.c:6580 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x166e/0x2830 mm/gup.c:1428 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860 __mm_populate+0x24c/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3701 [inline] vm_mmap_pgoff+0x38a/0x4d0 mm/util.c:586 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa2fb27f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa2f94de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fa2fb4d5fa0 RCX: 00007fa2fb27f749 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fa2fb303f91 R08: ffffffffffffffff R09: 0000000000003000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa2fb4d6038 R14: 00007fa2fb4d5fa0 R15: 00007ffc4945c618