INFO: task syz.5.15107:28047 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.15107 state:D stack:27568 pid:28047 tgid:28046 ppid:25981 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7379 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821 nfsd_nl_version_get_doit+0x17c/0xd20 fs/nfsd/nfsctl.c:1873 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x9b9/0xa20 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmsg net/socket.c:2770 [inline] __do_sys_sendmsg net/socket.c:2775 [inline] __se_sys_sendmsg net/socket.c:2773 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773 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: 0033:0x7fe50a79ce59 RSP: 002b:00007fe50b5a7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe50aa15fa0 RCX: 00007fe50a79ce59 RDX: 0000000020048000 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007fe50a832e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe50aa16038 R14: 00007fe50aa15fa0 R15: 00007ffd71e26bd8 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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: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+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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30034 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__queue_work+0x563/0xff0 kernel/workqueue.c:2323 Code: 8e 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 20 69 a4 00 89 6c 24 04 4d 03 37 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 f7 e8 03 69 a4 00 4d 8b 36 e8 bb 08 1b 0a 89 c5 31 ff RSP: 0018:ffffc90000a08bd0 EFLAGS: 00000046 RAX: 1ffffd1ffff604ac RBX: 000000000000001e RCX: ffff8880af1e0000 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000008 RBP: 0000000000000001 R08: ffffffff9340cba7 R09: 1ffffffff2681974 R10: dffffc0000000000 R11: fffffbfff2681975 R12: dffffc0000000000 R13: ffff8880b2c55378 R14: ffffe8ffffb02560 R15: ffffffff8e27c7d8 FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff2ffa6f52 CR3: 000000000e746000 CR4: 00000000003526f0 Call Trace: 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:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 9d ca f7 f5 f7 c3 00 02 00 00 74 05 e8 10 87 23 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e4 e1 e8 f5 65 8b 05 2d a4 8f 07 85 c0 74 18 5b 41 5e e9 91 48 RSP: 0018:ffffc90004f3f860 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000286 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: 0000000000000001 RBP: ffffea0001a98950 R08: ffffffff903116f7 R09: 1ffffffff20622de R10: dffffc0000000000 R11: fffffbfff20622df R12: 0000000000000f15 R13: ffffc900108ba000 R14: ffffffff9a713118 R15: 0000000000000000 __debug_check_no_obj_freed lib/debugobjects.c:1163 [inline] debug_check_no_obj_freed+0x39e/0x450 lib/debugobjects.c:1184 remove_vm_area+0x1c4/0x2f0 mm/vmalloc.c:3330 vfree+0x63/0x330 mm/vmalloc.c:3453 kcov_put kernel/kcov.c:444 [inline] kcov_close+0x28/0x50 kernel/kcov.c:543 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x73a/0x2360 kernel/exit.c:1004 do_group_exit+0x22d/0x2f0 kernel/exit.c:1147 get_signal+0x121b/0x12c0 kernel/signal.c:3038 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 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: 0033:0x7fc311b57fd7 Code: Unable to access opcode bytes at 0x7fc311b57fad. RSP: 002b:00007ffc85776860 EFLAGS: 00000202 ORIG_RAX: 000000000000003d RAX: fffffffffffffe00 RBX: 000055558e43a500 RCX: 00007fc311b57fd7 RDX: 0000000040000000 RSI: 00007ffc857768bc RDI: ffffffffffffffff RBP: 00007ffc857768bc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 R13: 0000000000000003 R14: 00007ffc85776b18 R15: 0000000000000000