INFO: task syz.4.9754:9734 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.9754 state:D stack:26552 pid:9734 tgid:9733 ppid:7481 task_flags:0x400140 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_rpc_status_get_dumpit+0xdc/0x13b0 fs/nfsd/nfsctl.c:1494 genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1026 netlink_dump+0x711/0xee0 net/netlink/af_netlink.c:2331 __netlink_dump_start+0x589/0x7b0 net/netlink/af_netlink.c:2446 genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1075 genl_family_rcv_msg net/netlink/genetlink.c:1191 [inline] genl_rcv_msg+0x5e1/0x7a0 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: 0033:0x7f22b279ce59 RSP: 002b:00007f22b3650028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f22b2a15fa0 RCX: 00007f22b279ce59 RDX: 0000000000000080 RSI: 00002000000000c0 RDI: 0000000000000005 RBP: 00007f22b2832e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f22b2a16038 R14: 00007f22b2a15fa0 R15: 00007fff1e657798 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: 17764 Comm: syz.6.11966 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:lockdep_hardirqs_on_prepare+0x6/0x270 kernel/locking/lockdep.c:4363 Code: 00 00 10 00 e8 1b 22 0d 03 89 c0 c3 cc cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 41 54 53 83 3d de 9f 8f 0e 00 0f 84 96 01 00 00 65 8b 05 01 RSP: 0018:ffffc900053a76c0 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000296 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: 0000000000000001 R08: ffffffff903117f7 R09: 1ffffffff20622fe R10: dffffc0000000000 R11: fffffbfff20622ff R12: 0000000000000000 R13: ffff888051d65000 R14: ffffffff9a6ec730 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1bb53ec4b8 CR3: 000000007c128000 CR4: 00000000003526f0 Call Trace: trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:178 [inline] _raw_spin_unlock_irqrestore+0x30/0x80 kernel/locking/spinlock.c:198 __debug_check_no_obj_freed lib/debugobjects.c:1163 [inline] debug_check_no_obj_freed+0x39e/0x450 lib/debugobjects.c:1184 __free_pages_prepare mm/page_alloc.c:1404 [inline] __free_frozen_pages+0x5a1/0xd20 mm/page_alloc.c:2938 tlb_batch_list_free mm/mmu_gather.c:161 [inline] tlb_finish_mmu+0x13e/0x220 mm/mmu_gather.c:552 exit_mmap+0x4b2/0x9f0 mm/mmap.c:1313 __mmput+0x118/0x420 kernel/fork.c:1181 exit_mm+0x221/0x2d0 kernel/exit.c:610 do_exit+0x6cd/0x2360 kernel/exit.c:992 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: 0033:0x7f2a6319ce59 Code: Unable to access opcode bytes at 0x7f2a6319ce2f. RSP: 002b:00007f2a6410d028 EFLAGS: 00000246 ORIG_RAX: 000000000000010f RAX: 0000000000000001 RBX: 00007f2a63415fa0 RCX: 00007f2a6319ce59 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000200000002000 RBP: 00007f2a63232e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2a63416038 R14: 00007f2a63415fa0 R15: 00007ffd858c7708