INFO: task syz.0.3700:18510 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.3700 state:D stack:26488 pid:18510 tgid:18508 ppid:14852 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_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2098 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: 0033:0x7f9fa6f9ce59 RSP: 002b:00007f9fa7eee028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9fa7215fa0 RCX: 00007f9fa6f9ce59 RDX: 0000000020040000 RSI: 0000200000000140 RDI: 000000000000000f RBP: 00007f9fa7032d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9fa7216038 R14: 00007f9fa7215fa0 R15: 00007ffe99f23388 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 25442 Comm: syz.5.5635 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:229 [inline] RIP: 0010:unwind_next_frame+0x205/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: 6c 04 00 00 44 89 f8 4c 8d 2c 85 24 a2 71 91 4c 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 4c 89 e3 0f 85 66 1d 00 00 45 8b 6d 00 <44> 89 f8 ff c0 4c 8d 24 85 24 a2 71 91 4c 89 e0 48 c1 e8 03 0f b6 RSP: 0018:ffffc90004d0f5a0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000080000000 RDX: 00000000000aaba9 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: ffffffff81aedaa3 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90004d0f698 R11: ffffffff81b10630 R12: dffffc0000000000 R13: 0000000000023ec2 R14: ffffc90004d0f648 R15: 000000000000aeda FS: 0000000000000000(0000) GS:ffff88812527c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f60f1 CR3: 000000000e746000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1397 [inline] __free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938 vfree+0x1fd/0x330 mm/vmalloc.c:3472 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: 0033:0x7f1d9575d68e Code: Unable to access opcode bytes at 0x7f1d9575d664. RSP: 002b:00007f1d92947e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: 0000000000000024 RBX: 00007f1d929496c0 RCX: 00007f1d9575d68e RDX: 0000000000000024 RSI: 00007f1d92948000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f1d92947f04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004 R13: 00007f1d92947f58 R14: 00007f1d92948000 R15: 0000000000000000