INFO: task syz.3.6757:30457 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.6757 state:D stack:25800 pid:30457 tgid:30456 ppid:27121 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_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1738 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: 0033:0x7fac7699ce59 RSP: 002b:00007fac7792a028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fac76c15fa0 RCX: 00007fac7699ce59 RDX: 0000000004040090 RSI: 0000200000000000 RDI: 0000000000000008 RBP: 00007fac76a32e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fac76c16038 R14: 00007fac76c15fa0 R15: 00007ffec647d3c8 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7245 Comm: syz.5.9313 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:unwind_next_frame+0xf3/0x2550 include/linux/rcupdate.h:-1 Code: 74 28 80 3d 53 56 a4 0e 00 75 1f c6 05 4a 56 a4 0e 01 48 c7 c7 40 a3 c9 8b be 4a 03 00 00 48 c7 c2 80 a3 c9 8b e8 fd 67 2b 00 <48> 89 6c 24 38 48 89 5c 24 40 49 8d 5e 50 48 89 d8 48 c1 e8 03 48 RSP: 0018:ffffc90005726c00 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff8ba75403 RCX: 0000000080000003 RDX: 0000000000000000 RSI: ffffffff8c291100 RDI: ffffffff8c2910c0 RBP: 1ffff92000ae4d9c R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90005726cf8 R11: ffffffff81b10630 R12: dffffc0000000000 R13: ffffffff8176a21f R14: ffffc90005726ca8 R15: 1ffff92000ae4d95 FS: 0000000000000000(0000) GS:ffff88812537c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3c837ea2f8 CR3: 00000000306f2000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3159 [inline] call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3279 xa_node_free lib/xarray.c:260 [inline] xas_delete_node lib/xarray.c:503 [inline] update_node lib/xarray.c:767 [inline] xas_store+0xe61/0x17f0 lib/xarray.c:852 page_cache_delete mm/filemap.c:142 [inline] __filemap_remove_folio+0x3e8/0x530 mm/filemap.c:228 filemap_remove_folio+0xf1/0x3a0 mm/filemap.c:258 truncate_inode_folio+0x5d/0x70 mm/truncate.c:176 shmem_undo_range+0x3fb/0x15d0 mm/shmem.c:1145 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x280/0xa80 mm/shmem.c:1407 evict+0x624/0xb50 fs/inode.c:828 dentry_kill+0x1b9/0x880 fs/dcache.c:826 finish_dput+0x1a/0x260 fs/dcache.c:1001 __fput+0x675/0xa50 fs/file_table.c:520 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: 0033:0x7fa15795d68e Code: Unable to access opcode bytes at 0x7fa15795d664. RSP: 002b:00007fa1588eae88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: 0000000000000020 RBX: 00007fa1588ec6c0 RCX: 00007fa15795d68e RDX: 0000000000000020 RSI: 00007fa1588eb000 RDI: 0000000000000007 RBP: 0000000000000000 R08: 00007fa1588eaf04 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000007 R13: 00007fa1588eaf58 R14: 00007fa1588eb000 R15: 0000000000000000